Haworthia Duv.: Section Retusae fide Scott — Additional Comment (1974)

Printed in Aloe 12:89 (1974).
M.B Bayer, Karoo Botanic Garden, Worcester.

The ‘retuse’ haworthias are among the most fascinating of the genus and therefore Colonel Scott’s recent revision is of particular interest.  This work…‘A revision of the genus Haworthia, Section Retusae” was published in ALOE, Dec.1973 and forms a new taxonomic record of the species involved.  The object of the present paper is to examine the validity of this record particularly in the light of past history of Haworthia.  A considerable literature on Haworthia is now available much of which points to the problems likely to be encountered in the group. Much of it also points to the consequences of inadequate species concepts for the group.

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The ‘Retuse’ Haworthias (1975)

Printed in Excelsa 5:83 (1975).
(This article was subsequent to the revision of the Retusae by C.L.Scott).

The 162 named species in the genus Haworthia Duval have been split into 20 sections of which Retusae Haworth is one.  The clearest and most obvious subdivision in Haworthia is into three subgenera which are based on both floral and vegetative characters.  The Retusae fall into the subgenus Haworthia which contains the soft- leaved stemless species in which the three outer petals of the flowers completely enclose the inner petals.  Division within this subgenus is the most difficult of the three and thus the composition of the section Retusae is understandably problematic.  The type species of the section is H. retusa (L.) Haw., so named on account of the fat, bent, thumblike leaves.  In theory this type of leaf should characterise all the other species in the section.  However, in the field it soon becomes apparent that apart from the difficulty in recognising and identifying “species” related to H. retusa, some of these related elements do not have retused leaves.  What then is the composition of the section Retusae and how can the individual species be recognised?  So far the only really satisfactory criterion we have is the geographic distribution and relationship of a large series of rather localised populations.  The individual plants in each of these populations differ to a greater or lesser degree from each other, and in similar manner, the populations differ from each other.  Thus we have variability within and between populations.  The composition of the Retusae is based here on visual assessment of the discontinuities of this variability, on geographic distribution, and on habitat.

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Haworthia Revisited – 32. Haworthia retusa

32. Haworthia retusa (L.) Duval, Pl.Succ.Hort.Alenc. :7(1809).  Haw., Syn.Pl.Succ. :95(1812).  Bayer :150(1976).  Bayer in Excelsa 8:46(1979).  Bayer :53(1982). pp Scott :112(1986).  Aloe retusa L. Sp.Pl. :322(1753).  Haw., Trans.Linn.Soc. 7:9(1804).  Type: icon, 2:t6 Commelin, Hort.Amstel.(1701):  H. foucheii V.Poelln., Succulenta 22:28(1940).  Type: Cape, Riversdale district, Grootvlei, Fouche.  Not preserved.  Neotype (designated here): CAPE-3421(Riversdale): Near Riversdale, Grootvlei (-AB), Dekenah 212 (NBG):  H. retusa var. multilineata Smith, JS.Afr.Bot. 12:3(1946).  H. multilineata (Smith) Scott :135(1985).  Type: CAPE-3421(Riversdale): 3km N. Riversdale, J. Dekenah 83 in Smith 5383 (NBG):  H. retusa var. solitaria Smith, JS.Afr.Bot. 12:5(1946).  H. solitaria (Smith) Scott, Aloe 11:37(1973).  Type (designated here): CAPE-3421(Riversdale): along Corrente River, 10km N Riversdale, Dekenah 5 in Smith 5373 (NBG):  H. retusa var. densiflora Smith, JS.Afr.Bot. 12:7(1946).  Type: CAPE-3421(Riversdale): Riversdale district, Venter 106 in Smith 5056 (NBG):  H. geraldii Scott, JS.Afr.Bot. 31:123(1965).  Scott, Aloe 11:22(1973).  Scott :132(1985).  Type: CAPE-3421(Riversdale): 5km east of Riversdale, Scott 72 (PRE).3

retusa: with leaf-tips bent back thumb-like.

Rosette stemless, slowly or seldom proliferous, to 12cm φ.  Leaves 10-15, turgid, rigid, with pronounced retused end-area, pointed tips, variously lined and windowed.  Without surface spination and usually without spination on margins and keel.  Colours brownish or green and seldom purpling.  Inflorescence simple, robust, to 30cm.  Flowers compacted on inflorescence, white with greenish-brown veins.

1982 – H. retusa is very closely associated with H. turgida, and an eventual re-evaluation of this association could lead to a total upheaval of species concepts in this group of haworthias.  H. retusa is taken to be an assemblage of forms in the Heidelberg and Riversdale areas, with clearly defined end areas, and points, to the leaves.  The various forms may or may not be proliferous, for example the var. solitaria was largely solitary, whereas the form described as H. geraldii is very proliferous.  The forms vary in cultivation and both dark and light green forms may occur.  The darker forms may have some relationship to H. magnifica, and the light forms to H. turgida.  The species is not well known in the area between Heidelberg and the Breede River and hence it is not known whether or not H. mutica and H. retusa intergrade.  H. mutica may simply be a blunt‑leaved form of H. retusa. The var. dekenahii from Albertinia is now thought to be represented by several populations in which plants have leaves very silver‑spotted ‑ a phenomenon which occurs in H. turgida too.  This variety may eventually be shown to link  H. retusa and H. pygmaea.  There is still an apparent break in the distribution of these two species between Mossel Bay and Albertinia.  The var. acuminata tends to be darker green and the leaves are very acuminate.  It occurs in the south‑east of the distribution range of the species and may also be expected in the area southwest of Albertinia ‑ still unexplored.

1999 – This revised treatment fulfils the predictions of 1982 amid the realisation that the views expressed there are correct, but stopping short of uniting H. retusa with H. turgida.  H. longebracteata Smith is now here regarded as a variant of that ubiquitous species and strictly H. geraldii Scott should be treated similarly.  However, the key issue is that H. retusa, as perceived here, is the robust, generally solitary forms which occur only in the Riversdale area.  Scott’s treatment is rather fortuitous in that he typifies the name in the same way, but applies it to the smaller clump-forming elements which comprise H turgida.  This is evident from his synonymy but totally compromised in his discussion where:- 1. he says it is restricted to one locality at Riversdale and two to three in the Little Karoo, and 2. the distribution map where localities at Little Brak and at Tradouw pass seem to be indicated.  Breuer and Metzing’s argument for the creation of an epitype, and also their choice, is also unfortunate.  The Commelin illustration could hardly be more distinctive and apart from Col Scott who muddled H. retusa and H. turgida, there has never ever been any sign of doubt about its application.  Furthermore, they select a specimen from the source of H. fouche.  The Commelin, illustration depicts the acute leaf-tips of the species very well and there is little chance of confusion with H. mutica

In the species concept for the genus, co-occurrence and consequent interaction, or lack thereof, are criteria for recognising species.  In the field it has become obvious that the interaction between species revolves around H. turgida as a main role-player and not H. retusa.  There is no interaction between the latter two named elements as they do not co-occur. The three species recognised by Scott viz. geraldii, fouchei and multilineata give a very good impression of the variation of this one species in the Riversdale area.  The var. solitaria may represent interaction with H. magnifica, and the vars. acuminata and dekenahii are both transferred to that species.  H. dekenahii var. argenteo-maculosa is treated as a variety of H. pygmaea.  The problem plants around Heidelberg are associated with H. mutica.

Distribution: 3421 (Riversdale): 8km W. Riversdale (-AA), Smith 5443 (NBG); Along Corrente River, 10km NW. Riversdale (-AA), Dekenah 5 in Smith 5373 (NBG), Dekenah in KG305/71 (NBG); 4km N. Riversadel (-AA), Smith 5493 (NBG); SW. Riversdale (-AA), Smith 5387 (NBG); Near Riversdale, Grootvlei (-AB), Dekenah 212 (NBG), Smith 4955 (NBG), Fourcade 263 (NBG), Bayer in KG627/69 (NBG), Bohnen 9058 (NBG); Blinkbonnie (-AB), Smith 6086 (NBG), Venter in KG 156/71; Zeekoegat (-AB), Smith 6089 (NBG); Ferguson Drive (-AB), Smith 5380 (NBG, PRE); 3km N. Riversdale (-AB), J. Dekenah 83 in Smith 5383 (NBG), Smith 5374, 5488 (NBG, PRE), Smith 6796 (NBG); 5km E. Riversdale (-AB), Scott 72 (PRE), Smith 5377 (NBG); Vet River Road (-AB), Smith 5383, 5387 (PRE); 14km E. Riversdale (-AB), Smith 5749, 7320 (NBG); Bolus 2868 (PRE); Commonage (-AB), Smith 5377 (PRE); Dekenah 11 (PRE); Riversdale (-AB), Fouche in PRE 34869; 3km E., Grootvlei (-AB), J. Scott 1778 (PRE); 3km E. (-AB), J. Scott 93 (PRE);

Inadequately located: Riversdale district, Venter 106 in Smith 5056, Smith 3432, 3850, 3919, 3962, 5043, 5056, 5599 (NBG), Bolus 11390 (BOL), Helm in NBG1746/32, Malherbe in NBG399/40, ex hort, Wilman in PRE 34904.

[ed. Bayer subsequently resurrected some of the varieties.]

H. retusa (Linné) Duval (Pl. Succ. Horto Alencon., 7, 1809). Type: [lecto — icono]: Commelin, Horti Med. Amstelod. 2: 11, t. 6, 1701. — Distr: RSA (Western Cape); Fynbos vegetation.

Aloe retusa Linné (1753) ≡ Catevala retusa (Linné) Medikus (1786) ≡ Apicra retusa (Linné) Willdenow (1811) ( incorrect name, ICN Art. 11.4).

H. retusa var. longibracteata (G. G. Smith) M. B. Bayer (Haworthia Update Vol. 7, Part 4, 36, 2012). Type: RSA, Western Cape ( Dekenah 18 in Smith 5378 [NBG, PRE]). — Distr: RSA (Western Cape). I: Scott ( 1985: 127, as H. longibracteata).

Haworthia longibracteata G. G. Smith (1945) ≡ Haworthia retusa fa. longibracteata (G. G. Smith) Pilbeam (1983) ≡ Haworthia turgida var. longibracteata (G. G. Smith) M. B. Bayer ( 1999).

Differs from var. retusa: L erect to suberect, ovate-lanceolate.

H. retusa var. nigra (M. B. Bayer) M. B. Bayer (Haworthia Update Vol. 7, Part 4, 36, 2012). Type: RSA, Western Cape ( Smith 5753 [NBG]). — Lit: Bayer ( 2004a); Bayer ( 2004c); Bayer ( 2005); all as H. mutica var. Distr: RSA (Western Cape: Heidelberg area).

Haworthia mutica var. nigra M. B. Bayer ( 1999) ≡ Haworthia silviae var. nigra (M. B. Bayer) M. Hayashi (2000); incl. Haworthia chromutica M. Hayashi (2000) ( nom. inval., ICN Art. 39.1, 40.1); incl. Haworthia quimutica Breuer ( 2011) ( nom. inval., ICN Art. 38.1a).

Differs from var. retusa: Ros more proliferous; L greener and more translucent.

H. retusa var. retusaDistr: RSA (Western Cape: Riversdale). I: Bayer ( 1982: Fig. 33a).

Incl. Haworthia fouchei Von Poellnitz (1940) ≡ Haworthia retusa fa. fouchei (Von Poellnitz) Pilbeam (1983) ≡ Haworthia retusa var. fouchei (Von Poellnitz) Breuer (2016); incl. Haworthia retusa var. densiflora G. G. Smith (1946); incl. Haworthia retusa var. multilineata G. G. Smith (1946) ≡ Haworthia retusa fa. multilineata (G. G. Smith) Pilbeam (1983) ≡ Haworthia multilineata (G. G. Smith) C. L. Scott (1985); incl. Haworthia retusa var. solitaria G. G. Smith (1946) ≡ Haworthia solitaria (G. G. Smith) C. L. Scott (1973); incl. Haworthia geraldii C. L. Scott (1965) ≡ Haworthia retusa fa. geraldii (C. L. Scott) Pilbeam (1983) ( nom. inval., ICN Art. 41.5); incl. Haworthia retusa var. quimutica Hayashi (2001); incl. Haworthia subretusa Breuer ( 2010) ( nom. inval., ICN Art. 36.1b, 38.1a).

Ros stemless, rarely slowly proliferating, to 12 cm ∅; L 10–15, turgid, rigid, with pronouncedly retuse end-areas, 8 × 2 cm, brownish or green and rarely with purplish hue, variously lined and windowed, surface and usually also margins and keel without spines or tubercles, tips pointed; Inf robust, to 30 cm; Fl 20–30, closely spaced, white with greenish-brown veins.

Possible hybridization with H. mirabilis is mentioned by Bayer ( 2012d).

H. retusa var. suberecta (Von Poellnitz) M. B. Bayer (Haworthia Update Vol. 7, Part 4, 36, 2012). Type [neo]: RSA, Western Cape ( Bayer s.n. in Karoo Garden 631/69 [NBG]). — Distr: RSA (Western Cape). I: Scott ( 1985: 126, as H. dekenahii).

Haworthia turgida var. suberecta Von Poellnitz (1938) ≡ Haworthia turgida fa. suberecta (Von Poellnitz) Pilbeam (1983) ≡ Haworthia suberecta (Poellnitz) Breuer ( 2010); incl. Haworthia turgida var. subtuberculata Von Poellnitz (1938); incl. Haworthia turgida var. pallidifolia G. G. Smith (1946) ≡ Haworthia turgida fa. pallidifolia (G. G. Smith) Pilbeam (1983) ≡ Haworthia pallidifolia (G. G. Smith) M. Hayashi (2010) ≡ Haworthia suberecta var. pallidifolia (G. G. Smith) Breuer (2016); incl. Haworthia pseuda Breuer ( 2010) ( nom. inval., ICN Art. 36.1b, 38.1a); incl. Haworthia reflexa Breuer ( 2010) ( nom. inval., ICN Art. 36.1b, 38.1a); incl. Haworthia rodinii Breuer ( 2010) ( nom. inval., ICN Art. 36.1b, 38.1a).

Differs from var. retusa: L strongly mottled, tips slightly truncate and rounded.

H. retusa var. turgida (Haworth) M. B. Bayer (Haworthia Update Vol. 7, Part 4, 36, 2012). Type [neo]: RSA, Western Cape ( Bayer 2420 [NBG 132378]). — Distr: RSA (Western Cape). I: Bayer ( 1982: Fig. 40, as H. turgida).

Haworthia turgida Haworth (1819) ≡ Aloe turgida (Haworth) Roemer & Schultes fil. (1829); incl. Haworthia laetevirens Haworth (1819) ≡ Aloe laetevirens (Haworth) Link (1822); incl. Haworthia caespitosa Von Poellnitz (1937) ≡ Haworthia turgida fa. caespitosa (Von Poellnitz) Pilbeam (1983); incl. Haworthia caespitosa fa. subplana Von Poellnitz (1938); incl. Haworthia caespitosa fa. subproliferans Von Poellnitz (1938).

Differs from var. turgida: Ros partially stemless, proliferous, 5–10 cm ∅; L 20–40, ovate-lanceolate, 4 × 1.2 cm, turgid, often as thick as broad, recurved or slightly retuse, margins and keel lightly spined.

H. retusa 138251
H retusa 122188
H retusa 62027
H retusa 7534
 Haworthia retusa (L.) Duval
Moninckx, J., Moninckx atlas, vol. 3: t. 7 (1682-1709)
 Haworthia retusa (L.) Duval
Commelin, Johannes, Horti medici amstelodamensis rariorum tam Orientalis, vol. 2: t. 6 (1701)
Haworthia retusa (L.) Duval
[as Aloe retusa L.]
Candolle, A.P. de, Redouté, P.J., Plantarum Historia Succulentarum, vol. 1: t. 45 (1799-1837) [P.J. Redouté]
Haworthia retusa (L.) Duval
[as Aloe retusa L.]
Botanical Magazine, vol. 13: t. 455 (1799) [S.T. Edwards]

Volume 5, Chapter 4:- Haworthia retusa – part 1

It has long been my stated contention that H. turgida is in fact a rock face ecotype as opposed to the solitary flat growing H. retusa.  Thus one should expect the multiplicity of forms that are found between, and consequently superfluous to say within each, these two primary types. There are problems outside of this and I will deal with those in the Chapter Haworthia enigma.  Here I am simply going to present pictures representing plants in nine populations of the species.  Most of these populations are of the “typical” solitary form and they all demonstrate variation to greater to lesser degree. Perhaps some special mention should be made of the element H. mutica var. nigra.  I have written at length about this and in doing so strayed widely into H. magnifica and its var. atrofusca (both falling now under H. mirabilis). This is because it is quite certain that there is an element of interaction in the field between the prime elements H. retusa and H. mirabilis  that this summation is intended to expose. The first known H. mutica var nigra from Kransriviermond is possibly the product of such interaction, whereas all the subsequent collections from northwards and westwards are now perceived by me to be variants of H. retusa and H. retusa ’turgida’ (to use a more informal and flexible way of communicating).

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Volume 5, Chapter 4:- Haworthia retusa – part 2

2. MBB7754 H. retusa ‘turgida’. Brakkekuil.  What is most significant about this population is its whereabouts that highlights the overwhelming importance of distribution and geography. The drainage systems (or parts of them) of the Southern Cape drain southwards from the mountains to the sea e.g. Gouritz, Goukou, Duiwenhoks and Lower Breede. These are important especially when it comes to the habitats in the way of exposed rock and steep faces that favour plants requiring skeletal soils. Brakkekuil is on the Slang River that drains southwestwards from near Heidelberg to flow into the Breede River near Malgas. H. retusa ‘turgida’ has not been reported for this entire river system before, while it is present on the Breede River and even westwards at Bredasdorp. So the Brakkekuil population is significant and also significantly different. The plants are neither strictly solitary nor greatly clump-forming and it is not really surprising as this mirrors what happens with H. cooperi in the Eastern Cape in situations that are neither fully cliff face nor plain. The Brakkekuil plants are on the surface of a rocky shale knoll with plants enduring direct exposure to northwestern sun as well as obtaining refuge in the more vegetated and protected slightly southern aspect. It is quite difficult to make reference of individual plants to Latin names, in that variation is already ensconced in the existing system viz. ‘longibracteata’. I gladly concede that all the old names, as Rowley has suggested, can be paraded out again and made use of. In fact I have also said that this is how the contribution of Breuer and Hayashi can be fruitfully used. For my reality this population is H. retusa ‘turgida’ Slangrivier. It is quite the most variable population of the ‘turgida’ side of H. retusa that I have ever seen and there are plants that resemble the more sandstone associated variants (‘caespitosa’) at, say, Tradouw Pass as well as individuals that compare with some of the other populations I will cover from the ferricrete inselbergs. Another very significant observation is the similarity of some plants to those that can be found in H. mirabilis ‘paradoxa’ that is not very far away to the southeast at Vermaaklikheid. There is no doubt that if a full and real understanding of natural systems is to be found it will lie in the realization that even my suggestion favouring a “super species concept” may be conservative. It is actually curious how my treatment of that has been met by readers who have been kind and considerate enough to communicate with me on the issue. The ‘super species” proposal actually comes from Prof Canio Vosa. It is and was not, any attempt to confound anyone or obfuscate the issue. Prof. Vosa is directly addressing the issue that we have a classification that is a sorry marriage of scientist and layman user groups – both ignorant of the full extent of the field situation.

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Volume 5, Chapter 10:- Haworthia ‘enigma’ and H. mutica var nigra.

7778 H. mirabilis. Komserante 4900

If the name “H.enigma” applies to the plant (or plants) from east of Riversdale at Komserante, it is a name that I really do not advise to be taken seriously from a botanical point of view.  It is useful at population level and to demonstrate the nature of classification difficulties but it is a minor problem in so far as those difficulties extend.  The plants were first shown to me by J. Dekenah on the same day that he also showed me ”H. magnifica” in the Nature Reserve just south of Riversdale that is less than 3km away. My impression then was that it was the same element even if it did look a bit different. The plants are quite large (to 70mm diameter), fairly tubercled and often with lines in the upper retused area of the leaf face.  While I originally classified “H. maraisii” under “H. magnifica”, I later separated them because it seemed so incongruous to include all the variants of the western “H. maraisii” with the few populations of “H. magnifica” then known.  Also, as Essie Esterhuizen pointed out, “H atrofusca” as a variant of “H. magnifica”, seemed to be more dominant than had been realized.  There were several other complications largely due to ignorance. Since my revision I have done so much more exploration and turned up so much new material that I have been forced to the conclusion that there is really one main element involved and that is H. mirabilis. This is where I believe the Komserante plants belong and the difference from the Nature Reserve population is due to a degree of infusion of H. retusa.

I revisited the site with Kobus Venter many years ago but did not look at a reported second population higher up the hill, taking it to be a little different based on plants I saw in Kobus’ collection. What was on my mind while we were recently exploring the area further east to examine the possible connection of H. mirabilis “magnifica” to “splendens” (and which we confirmed), was the fact I had never seen Kobus’ plants from Kruis Rivier northeast of Riversdale other than in Kobus’ collection. The plants I saw were also generally more robust than “H. magnifica” and more evenly tubercled. Kobus kindly took me to that Kruis River locality and much to my surprise the plants were in flower late October (see JDV92/65 Figs1). This is quite wrong for H. mirabilis, which is essentially a summer flowering species. I later went again to explore Komserante more thoroughly and to look at both the “magnifica” populations to which I believe the name “H. enigma” has been applied.  he populations are in fact no more than 75m apart and cannot be considered to be genetically discrete at all (see MBB7778 Figs 2, and MBB7779 Figs 3). While it is true that the habitats are slightly different, this is reflected in the plants that at the upper slope of the hillside are vegetatively more robust and even clump forming, while those lower down in a bushier grassier habitat tend to be solitary and more withdrawn into the soil. These plants flower in summer and it is evident to me that there must have been some genetic exchange with H. retusa that grows approximately 200m away on the same hillside.

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Volume 5, Chapter 13:- A February 2009 Miscellany

7807 H.minima.  Swartrug, SE Heidelberg. 002

This chapter is based on recent field exploration and embroiders around many aspects of Haworthia species discussed in earlier chapters.  What should be striking is that new populations follow the very predictable geographic pattern that all my earlier exploration has exposed and in my estimation confirm in every way what I consider a sound and satisfactory taxonomic solution and help explain its limitations.

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Volume 5, Chapter 16:- Can Haworthia teach us anything?

My experience with Haworthia dates back to my childhood and on to nearly 70 years of observation.  However, my interest was only able to properly manifest when I began work at the Karoo Botanic Garden in 1969 and it has since been through many phases.  I wrote a formal taxonomic revision of the genus in 1999 and have spent a good bit of the last nine years adding to and verifying what I wrote.  Haworthia has always been regarded as a problem child of botany to be avoided by professional taxonomists for various reasons including an apparent phobia of the many amateur collectors peering over the shoulder while at work.  This has puzzled me because it seemed to me that if the need for good classification and identification was so strong there was an obligation on botany to provide the service.  So my involvement has been largely by default.  I was trained in an agricultural and entomological tradition with a totally different and unsophisticated approach to things like taxonomy, systematics and nomenclature.  In the infant science that agriculture then was in South Africa, I can barely claim that my MSc is much more than an indication that I tried to learn something beyond normal schooling. While trained as an agricultural entomologist, my leaning was to plants and I eventually came to the Karoo garden to do what I liked best viz. exploring plants.  Unfortunately the route is via identification and names and so I have walked a long road through the minefield that this is.  Was this only in respect of Haworthia?  No!  This is a persistent misconception.  Haworthia is only different because it has attracted such close and sustained amateur interest by so many for so long.  I experienced failing classification in many other genera.  To be fair I think the real reason is the lack of importance attached to the whole function of plant classification.  It even seems as if many modern botanists pursue the study of plant relationship under the guise of systematics that is not committed to providing formal names and identifications.

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Volume 6, Chapter 2:- Towerlands. Haworthia retusa ‘turgida’

In Haworthia Update 4 I wrote an essay about the haworthias east of Albertinia in which I discussed their relation to H. retusa  and H. mirabilis, while generally lumping them largely in H. pygmaea.  There are of course real ‘turgida’ populations as far east as near Mossel Bay, so I argued the case for an interplay of the two former species that over the whole distribution range generated two ‘species’ in the east viz. H. pygmaea and H. retusa (to include ‘turgida’), and three ‘species’ in the west adding H. mutica to H. mirabilis and H. retusa.

Recently I had the pleasure of meeting Gregory Nicholson who is studying botany at University, Cape Town.  He surprised me by telling me that there was a Haworthia on his parent’s property west of Herbertsdale.  It was not in fact so much surprising as confirmation of the belief I formed on a trip a short while before that there must be haworthias in the very suitable terrain of the Jakkals River valley 6km west of Herberstdale.  The surprise came when Greg indicated the position of the plants much deeper into the mountains.

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Volume 7, Chapter 1:- Haworthia retusa ‘nigra’ – Another grand finale.

I wonder.  I have written so many words purporting to be my last that my credibility here too must be under stress.  Two very recent articles of mine in Alsterworthia deal essentially with that issue, although they also cover the discovery of Haworthia mutica (Buffeljags) (= H. groenewaldii Breuer).  They do not cover my subsequent thoughts on actually reading the description of this new “species” by Breuer, Marx and Groenewald.  I hope that the present manuscript will explain why I reject this as a Latin binomial although anyone who is in the least familiar with my writing should already know.  Spurred on by that discovery, I instigated a search in another area of the Buffeljags valley adjoining the Bontebok Park accompanied by Jannie Groenewald who informed me of what he had found in still another area I had long wanted to explore.  So I instigated another search there too and again with Jannie.  A discussion of these new finds is submitted to Cactus and Succulent Journal where I trust it will be published.  The essence is already in Alsterworthia and this article is written to widen the readership, submit more pictures and maintain continuity with the 6 volumes of Haworthia Update that Harry Mays has been so conscientiously and determinedly publishing.  This is all writing that may not otherwise have seen the light of day.  I am personally extremely grateful for that as I have had a mania since writing my revision Haworthia Revisited and Update Vol. 1 (both Umdaus), to set the record straight and explore all the unknowns, or at least some of them.

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Volume 7, Chapter 6:- Field trip to Van Reenens Crest and Niekerkshek.

M B Bayer, PO Box 960, Kuilsriver 7579, RSA.

The objective was to explore some likely habitats previously observed at Van Reenens Crest and nearby.   We extended the scope to include further exploration for Haworthia mutica as I am still questioning the place of this species in the greater scheme of things.  Thus here are four sets of populations that I report on viz. H. mirabilis, H. retusa ‘nigra’, H. floribunda and H. mutica.  See maps Figs 1 and 2 for geographical position.

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My view of names

There seems to be so much harping about my departure from the International Code of Botanical Nomenclature (ICBN) that I obviously need to try and explain myself better.  The real issue is that we are dealing with a group of plants that is largely appreciated for its vegetative characters and not for its small and unexceptional flowers. Because the plants are small and so commonly grown by collectors the numbers of plants in cultivation and close observation is large. The plants also do vary in respect of leaf morphology, arrangement, and surfaces to a greater extent than in many other genera.  Furthermore, the variation is also exaggerated by growing conditions. The fact that flowers are not used in the classification process beyond the level of sub-genera means that there is an almost total reliance on vegetative characters for classification. The nomenclatural system in botany tends to be a typological one, which means that reliance is placed on descriptions very often derived from single specimens. This is particularly so when the nomenclatural types are simply old illustrations that have been used to arrive at identifications and names by consecutive authors for decades. Thus use of those identifications and names, and their continuing re-interpretation causes a great deal of either grief or great personal satisfaction depending on just who is being affected by the process. The fact that the names should indicate “species” is lost from sight and totally obscured by the additional absence of any good universally accepted explanation for what a species is or might be.

Explanation in and around all this has been a large part of my writing since I started this in 1962. Thus I will not enlarge on the subject but rather try to explain again this way using a species name generated by Col C. L. Scott with whom I had some considerable altercation. It must be understood that Col Scott was not a biologist and it is just a simple fact that the problems that the above brief remarks expose, trouble many professional taxonomists to this day. I do not condemn Col Scott and express my respect and admiration for him and am very grateful to him for the friendship he later extended to me before he died.

The example I will take is that of his species Haworthia geraldii.  It comes from a small hillside east of Riversdale running south to north, named Komserante. This is an Afrikaans term meaning the ridge around a small geographic basin.  In the way that Haworthias are assembled in small habitat defined and localised populations, there are three recognizable populations of plants (of the subgenus Haworthia) along this one ridge about 1km long.  The southern population used to be complemented by still another that occurred where the stream bed left the basin at the southern end. A plant from that southern population was named as H. foucheii by K. Von Poellnitz. The northern population is a bit problematic and I initially included it in my then concept of H. magnifica. Since then however, it has become clear to me that my idea of species was too conservative and that H. magnifica as described by Von Poellnitz from south east of Riversdale (now the Frehse Reserve) is part and parcel of a huge complex that I regard as H. mirabilis.Thus this northern population is seen by me as H. mirabilis but complicated by the fact that it is largely influenced by hybridization with the next population or populations south. A plant (or perhaps, and doubtfully, plants) have been given the name H. vernalis by the Japanese writer M Hayashi. The name H. geraldii is attached to the second population southwards. The plants are very proliferous, form large clumps and the leaves are usually quite strongly retused (“bent back like a thumb”). The name H. foucheii is simply attached to the third because the plants there tend to be solitary and the leaves are also fairly erect and spreading as described and pictured for the original from the fourth population that was off the ridge.

The problem is now that we have descriptions and plants in each population that do not match the descriptions. While I assign the northern population and all the plants in it to H. mirabilis, other writers use the names H. vernalis, H. magnifica and even the confused name H. asperula. What they mean is by no means clear and in actuality a lot more names and descriptions would then be required to name each of the countless variants there for what might be an original pure species and variants or for first second or third generation hybrids with H. geraldii or H. foucheii as those names were applied.

But the problem is far more extensive than just these four populations. After years and years of field exploration it has become evident to me that like H. mirabilis, H. retusa is also highly diverse and I see it to include all the variants of H. turgida. In fact I suggested a long time ago that H. retusa is simply the solitary large form of H. turgida in low-lying level areas as opposed to the more common and extensive clumping cliff dwelling forms of that species. This is also why I object to the requirements of the ICBN that require the name H. retusa to take precedence for the species for historical reasons when it would be far more realistic to take it as a variant of H. turgida for biological reasons.

It has always been simply evident to me that H. geraldii and H. foucheii are variants of H. retusa. The problem now is that the plants in the two populations vary so much that, while the names are indeed useful for commercial and collector use, there can be problems that the use and application of the names will be confused.

Look at it like this. In respect of H. geraldii; it came from one population at Komserante, Riversdale and not all the plants are the same. I think this one population and all those plants in it belong to the species H. retusa, so I called it H. retusa var. geraldii. (var. = variety). Because not all the plants look the same that means that only some are truly geraldii and only the plants that meet Scott’s description are actually var. geraldii. Because the plants multiply vegetatively and Scott only took a piece, the original plant may still be there.  This means that we should recognize it as H. retusa var geraldii forma geraldii and in cultivation as H. retusa ‘Geraldii’ or just as H.  ‘Geraldii’. What do we do with the other 100 plants or more in the population that are not H. retusa ‘Geraldii’?  I do not think they can all get names so I take away the capital letter, leave out “var.” and use ‘ and ‘ (inverted commas) to show that the identification is, and will, be a bit uncertain unless you know from a label that the plant comes from that particular population at Komserante. The same applies to H. retusa var foucheii.  In this case the original population is gone and I am not sure if H. ‘Foucheii’ is still in cultivation. So I use the name H. retusa ‘foucheii’ for a second population on Komserante. Some of the plants in this population look like some of those in the H. retusa  ‘geraldii’  population but not quite like H. ‘Geraldii’ itself. So for me the answer is MBB7780 H. retusa ‘geraldii’, Komserante and MBB7781 H retusa ‘foucheii’, Komserante.

It can be seen that a complication comes in when more than one population is involved.   The problem then is that you can put them in a line so that some plants in the first population look like plants in the second, some in the second look like plants in the third, some of those look like those in the fourth until at the end none of the plants in the last population look like any in the first.  The trouble in the field is that the line is not straight and it can also go off in different directions.  Some of those directions may end up where they started.  One simply cannot be truly confident about many of those names that are given to plants.  Serious and proper consideration must be given for how different they may be even within the populations.  Not to say of the shared similarities and still added variation from geographically adjacent populations.  It may happen that I may write H. ‘retusa’ (and add number and place name) for a population that may better (not necessarily correctly) be identified as H. retusaXmirabilis.  Other writers who are not biologists and have other considerations in mind may want to give a new name altogether.  That new name and description may be again really only for one plant, or maybe a few more in a population, that have real or imagined novelty value and attraction.  But they take no account of all of the less attractive variants or other populations that comprise the biological whole by close proximity if for nothing else.

The above discussion is integral to the rationalized list of names that Dr John Manning helped me produce. There are some species names there that I have deliberately presented as synonyms or variants of the species I recognize, because the authors of those names fail to convince me that they have any understanding of the situation at all.  The word “species” is apparently simply a convenient naming system for oddities and novelties and not any scientific construct to explain the natural phenomena of living systems and their parts.

To summarize; I have written a report on flower characters in which I refer to the Komserante populations and I have used the following names and my own convention as follows:-

Please note that the way I have omitted the word variety from the following names and also used inverted commas …

7779 H. mirabilis, Komserante (the northern population – I could add ‘vernalis’ but it carries all the baggage of doubt about actual status).

7780 H. retusa ‘geraldii’, Komserante.

7781 H. retusa ‘foucheii’, Komserante.

7920 H. retusa ‘ nigra’,, Van Reenens Crest.

The omission of the word variety is for two reasons…

1. Economy

2. To convey the idea that the actual indication of status is not certain as I have used the name to indicate a population or populations rather than a single described plant.  The prime and overriding uncertainty is that we cannot know what a species is that I have described for Haworthia.  Thus how can we possibly rank populations at levels below?

The use of inverted commas reinforces what I want to convey. This is that the individual plants in the populations are variable and it may not be easy to always identify the plants (individual or population) according to a more formal classification.

Any departure from the ICBN or the way the names are treated in formal botany conveys the difficulty that I personally find in trying to reconcile formal nomenclature with names that are so often tied to single plants.

New finds in Haworthia.

Previously published Cact. Succ. J. (Los Angeles) 84(1): 41-50

Map - east of Swellendam

Map Legend – east of Swellendam.
1. JDV84/75 Haworthia retusa ‘turgida’.
2. MBB6666 H. retusa ‘nigra’↔ H. mirabilis.
3. MBB7898 H. retusa ‘nigra’.
4. MBB7899 H. retusa ‘nigra’.
5. MBB7897 H. retusa ‘nigra’.
6. MBB7896 H. retusa ‘nigra’.
7. MBB7871 H. mirabilis.
8. MBB7823 H. mirabilis.
9. MBB7909 H. mirabilis
10. MBB7805 H. mirabilis.
11. MBB7801 H. mutica ‘groenewaldii’.
12. MBB7886-7889 H. mutica ‘groenewaldii’, H. mirabilis, H. minima, H. marginata.
13. MBB7722 H. floribunda ‘major’

1. Haworthia marginata and H. minima

 The Robustipedunculares  is quite a distinctive group within the currently recognized genus.  While the four species in the group are generally quite distinct, there are some remarkable complexities that rival that elsewhere in the genus.  Recognizable and obvious hybrids are found between H. marginata, H. pumila and H. minima, but there are instances of whole populations that appear to consist of such in-between forms e.g. H. Xmortonii.  I have speculated that perhaps rather than have just hybridized, the species have never ever really truly separated in the supposed evolutionary process.  There is a vast body of variants that still link them in intimately as this piece will show.

I long ago observed that a small remnant population of ostensibly H. minima just south of Swellendam flowered in November as opposed to the general rule for the Robustupedunculares as late summer flowering.  A vicarious population at Brandrivier north of the Langeberg (H. minima ‘opalina’) also flowers in November and both populations have fairly large and white flowers for the species.

I have recorded the normal bluish-green H. minima within the Bontebok Park at Swellendam as well as a very green variant.  But in very recent exploration to the south-east we found an even more divergent group of plants that, while varying among the plants, seemed to be hybrids of H. marginata and H. minima (fig. 2 as a single sample and not representative of all).  It was September and there were no signs of old or new flower spikes.  Kobus Venter, who was present, remarked that the first plant seen was reminiscent of the plants once present south of Swellendam.  The plants were large and in exposed situations even colored brownish as does H. pumila.  No flowers were present and their color may have shown if H. pumila could have been directly involved at all, while it is essentially its distribution restricted eastwards from the Robertson Karoo by some 20km that reduce the possibility.

What makes the situation more interesting is that nearby was a population of H. marginata that was flowering and the flowers were also large and very white for the species (figs 3 & 4).  Added to the fun was a smaller probable hybrid (fig. 5).

Differences and complexities like this do not really surprise me because it is what I have come to expect in my many wanderings in the field.  The problem is that it certainly makes classification and any agreement on a set of names very difficult.  I just accept it as a fact that plant species can exhibit greater differences between individuals of the same species than between individuals of different species, ridiculous as it may sound.  This is because I perceive species as systems of individuals in populations with a very strong geographic component.  To actually make a decision it is frequently necessary to determine just what else is growing in the vicinity in respect not only of the genus in question, but also that of other plants.  Even the habitat factors need to be considered.

In the case of the plants pictured with this, the Bontebok Park terrain is mostly tertiary gravels, while the habitat we found the plants in was more recent riverine boulders.  It is very curious that in the description of H. groenewaldii, the habitat is implicitly described as Ruens Silcrete.  I do not think this is true.  It is in the true Ferricrete/Silcrete that we found the next and it seems to be these differences in substrate geology that play a large role in generating variation and consequent controversy.

2. Haworthia retusa ‘nigra’

I first allied this element with H. mutica because this is how G.G.Smith referred to his collection from Kransriviermond south of Heidelberg.  Since then there have been many new collections from which can be gathered that this population is a hybrid one between H. retusa ‘turgida’ and H. mirabilis.  There is another collection north of this at Morning Star that appears to have the same parentage but also including H. floribunda.  Then there are populations continuing up the Duiwenhoks and then Klip rivers to northwest of Heidelberg, a population between Heidelberg and Tradouw Pass further west and also a population at Goedverwagting south from there.  Apart from the Morning Star population (February/March) these are all September/October flowering.  There is a population at the southern entrance to Tradouw Pass of the same ilk that is February/March flowering.  Then there is quite a distance between these known populations and a remarkable population at Buffeljags south of Tradouw Pass.  It is remarkable for the fact that it is lauded as a new species viz. H. groenewaldii when I consider it to be generated from the interaction of H. mirabilis, H. mutica and H. floribunda.  I attach no special importance to the fact that it flowers, contrary to H. mutica, in February/March.  This is because I have observed many hybrids between patently different species despite a seasonal difference in flowering time.

To explore the realities of the situation we undertook two expeditions, one was to Buffeljags to explore west of H. groenewaldii and the other was to the Tradouw Pass area to explore H. retusa ‘nigra’.  The first exploration yielded three populations of ‘groenewaldii’, which convince me that despite its flowering time as for H. marginata above, is simply H. mutica in another guise.  I also think far too much is made of superficial and trivial differences that are as much characteristic of the variation in the one original population as they are within the four populations and for H. mutuca in its full sense.   I consider it significant that H. mirabilis in its more normal non-retuse and dark green form is present in discrete populations both at and west of Buffeljags.

The second expedition was nearly as fruitful.  It showed the Tradouw Pass population to be February/March flowering (see figs 6 & 7), while three new populations we discovered between there and the previous records in the easterly Heidelberg direction were Sept/October flowering.  They link up to the populations elsewhere that I assign to H. retusa ‘nigra’.  An additional find by Jannie Groenewald, for whom that H. mutica viz. H. groenewaldii, variant is named, also took us to a population of what is clearly H. mirabilis (see map) as I know it in its many disguises in the white kaolinic/bentonite clays of the silcrete/ferricrete inselbergs throughout the low-lying Southern Cape.  There is unquestionably an overlap of characters between what I assign to H. mirabilis and H. retusa and I consider inarguable that H. mutica is a reflection of a shared gene pool.

What this demonstrates again, as does the Kiewietsvlakte populations between Heidelberg and Riversdale, that H. retusa and H. mirabilis are closely intertwined from east to west.  There is an added complexity that H. floribunda is admixed along the northern populations and H. variegata along the southern.  The admixture of the two species produces H. retusa ‘turgida’  and H. pygmaea in the east and H. mirabilis, H. mutica and H. retusa ‘turgida’  in the west.  This is complicated by the other interactions along the northern and southern areas.  In the Potberg area it appears that the genetic material of all five “species” is evident in the populations that I have seen there.

While I would like to explain the situation around H. groenewaldii I. Breuer that I interpret as a variant of H. mutica, this should be left for another occasion as too many images are required to support any argument.  As it is, the issue of H. mutica ‘nigra’ occupies 29 pages and 79 illustrations in my book Haworthia Update Vol.2 pt 1:50., where all the above mentioned variants are discussed and illustrated.  The naming of Haworthias is highly contentious because the species consist of aggregates of small fairly isolated populations that may differ to large or small degree.  The populations are in turn also aggregates of plants that can all be identical from vegetative propagation, similar because of low genetic difference or very different from each other because of large genetic differences.   Therefore figures 6-13 simply show just a sample of the variation within these four populations in the Tradouw Pass area.  The plants vary quite considerably in size too and the one in Fig 8 is nearly 200mm diameter.  I have added to the map locations of the only significant other populations that I know of in the area including H. retusa ‘turgida’ and H. floribunda ‘major’, excluding those within the Bontebok Park viz. H. minima, H. mirabilis and H. marginata.

Perhaps I should close by explaining that I have dropped the use of any rank below that of the species name.  I simply am suggesting that we recognize the need for a trinomial system without the pretension of status, and more greatly honour the binomial as an entity of a greater significance than we may know.   I do this because botany has no proper species definition and consequently species descriptions are just based on wild guesses about possible non-similarity and on the flimsiest of supposed character differences.  The loosely used word “typical” is only truly useful in respect of the one plant dried as an almost unrecognizable specimen that is used to anchor the Latin name.

Acknowledgement. Any proper excursion into Haworthia territory always requires acknowledgement of landowners and I thank Jaap Viljoen and Jannie Groenewald for organizing that and for their company.  I was also glad to have Kobus Venter along who had persuaded me to show him some of populations known to me on promise of new exploration.

Cross seasonal hybrids observed are-

H. retusa turgida X H. floribunda Blackdown, Heidelberg.

And also Platjieskop, Riversdale.

H. pygmaea X H. floribunda Coopert Siding, Albertinia.
H. mirabilis
X H. retusa Soetmelksrivier, Riversdale
H. mirabilis X
 H. variegata Stoffelsriver, Swellendam.

References. I need to record that Harry Mays of Alsterworthia kindly undertook the non-profitable publication of 5 volumes of Updates (2-6) between 2006 and 2009.  Vol. 1 was published by Umdaus in 2001. These volumes were the product of research to validate or correct what appeared as a formal revision in Haworthia Revisited, published by Umdaus in 1999.  The description of H. groenewaldii appears in Alsterworthia 11.2:15 (2011).

Still another view of Haworthia retusa and Haworthia mirabilis

I recently wrote an essay on the situation between Haworthia retusa and Haworthia mirabilis at Komserante east of Riversdale.  The essay was entitled “My view of names” and is posted on the HaworthiaUpdates.org web site.  Etwin Aslander posted some pictures from what he called Kruisrivier.  These caught my eye because they did not look like the plants I know from a place of the same name.  My known population is JDV95/62 and generally these plants have the dark colour and rough surface texture of H. mirabilis.  The issue is that they are spring flowering whereas H. mirabilis is generally considered and observed to be late summer flowering.  Etwin indicated to me where he had found his plants and I duly went to look.

In the process I incidentally called on a well known H. retusa population at the Skietbaan locality south of Riversdale.  There has been a dramatic turnabout in the appearances of these plants since I last looked there 2 years ago.  Whereas there were then huge clones well above ground level, the plants were now again smaller and drawn into the ground.  I experienced this dramatic shift in plant appearances just west of the Frehse Reserve many years ago when there were giant size plants as opposed to my first visit when the plants were really small and withdrawn.

Kobus accompanied Daphne and I to Kruisrivier where the owners Wilhelm and Mandi Zietsman were extremely helpful. They told us also of a neighbor, Gert van Rensburg, who had also seen the same plants on his farm to the west. Mandi accompanied us on a jaunt to find that farmer and failing that we explored north of the original Kruisrivier locality. There we found another population of plants as well as H. floribunda (see Set 1 MBB7998). These two species H. retusa and H. floribunda were occupying different habitat and spaced about 100m apart. The H. floribunda was numerous and rather smooth leaved as well as paler green in colour than I expect from that species. The H. retusa-like plants were much smoother in surface texture than the original known population and they were in bud (see Set 2 MBB7999). We went back to the older population just to confirm that they were in bud too as we expected. Just so and the buds were just emerging from the rosettes. The plants were generally smaller than they were at a previous visit (see set 3 JDV95/62).

We parted company with Mandi Zietsman, and went off westwards intended to explore the Klein Kruisrivier area that seemed to better fit Etwin’s site indicator.  By good fortune we ran into Gert van Rensburg of Wegwysersrivier. He eyed us very suspiciously indeed and obviously very reluctant to show anyone the plants. However, he very kindly relented, took us to the spot and left us to freely photograph and explore (see set 4 MBB8000). The plants can be described as midway between the generally rougher surfaces of JDV95-62 and the smooth surfaces of MBB7999. What was more dramatic is that there were six flower spikes so that flowering is possible as early as July 6th.

We returned via another route regretting leaving distant habitat unexplored.  But we did find another population of H. floribunda, a little more toothed and perhaps brighter green than at Kruisrivier.

I also note that I long ago confirmed Smith’s record for H. retusa ‘turgida’ at Klein Kruisrivier in the upper Wegwysersrivier Gorge. This is the small spinose proliferous version known elsewhere from the Langeberg Mts.

Digesting this new information is a bit difficult in view of the very opposed views of what names mean and how they should be applied. Taking all the populations that I have explored and written about, my perspective is further to a view expressed in Haworthia Update 7.  This is that H. retusa and H. mirabilis are uncomfortably close. The only thing that appears to separate them is the yellowish green and smooth tendency in H. retusa and the darkish green and surface rough tendency in H. mirabilis. Further to that is of course the question of spring flowering versus late summer flowering. But I have already reported several case of hybridization across this divide as well as the Komserante situation. Here we now have plants in three populations that occupy middle ground and one of these populations has a significant degree of a winter flowering capacity. The identification should perhaps utilize the chemical equilibrium symbol. This is not quite it “↔” as the better symbol comprises halved arrows pointing in opposite directions.

I wish to add that in the case of plants I attribute to H. ‘turgida’ at Towerlands, I commented on the very real possibility of a close connection to H. emelyae.  There is also evidence for this elsewhere. I use the name ‘turgida’ like this because of the uncertainty of it really being H. retusa var. turgida or perhaps H.  pygmaea.

My experience in other situations viz. H. limifolia, H. herbacea/H. reticulata, H. arachnoidea/H. mucronata, H. cymbiformis/H. cooperi, Kiewietsvlakte etc. all suggests to me that the view of species is grossly distorted in the splitter direction. It is clear to me, if to no one else, that H. retusa and H. mirabilis form a very cohesive entity with ramifying oddities the length and breadth of the distribution range. I do not cover this issue here, but there is the added complication of the involvement of H. floribunda. It seems to be very discrete in most places, whereas at others it seems to get lost mainly (only?) in H. mirabilis. This may be because the introgression is favoured by the same flowering season. H. retusa and H. mirabilis are drifted apart by the difference in flowering season but it is by no means anything more than a general observation.

I have added the images of the available flowers as well as that of a bud to show the flared fishtail bud-tip that the southern Cape species tend to have. The flowers are variable and it is difficult to make a statement that characterizes them i.e. no composite image forms.

Acknowledgement: I would like to acknowledge Etwin Aslander’s input. Wilhelm and Mandi Zietsman were extremely helpful. Gert van Rensburg was surprisingly well informed about the plants too and very generous in his attitude to us. Part of the pleasure of field work is meeting people like this.

Set 1. MBB7998 H. floribunda Kruisrivier

Set 2. MBB7999 H. retusa Kruisrivier

Set 3. JDV92/65 H. retusa Kruisrivier

Set 4. MBB8000 H. retusa Wegwyserivier

MBB8000 flower faces

MBB8000 flower profiles

MBB8000 flower bud

8000 H. retusa, Wegwysersrivier. Flower bud.

Addendum: To demonstrate the problem of similar looking plants that appear in different populations, I take 3 plants from the original Kruisrivier population (JDV92/65) see figs 1 to 3.  Fig. 1 is obviously a mirabiloid plant and if this population flowered in late summer it would probably be identified as H. mirabilis. The figs 2 and 3 are more retusoid. I leave out plants from the newer Kruisrivier population (MBB7999) because none of the plants have the rougher mirabiloid leaf surfaces.  I add a Wegwysersrivier (fig. 4 MBB8000) plant that is again mirabiloid and like Fig. 1 except that it appears to be a spring flowering population with a significant number of plants in flower in early July.  From there I take a plant from Komserante (MBB7779) that flowers in late summer but is apparently generally hybrid with H. retusa.  Moving eastwards from Riversdale and impinging on H. mirabilis splendens, I show a plant MBB7762 from Platkop (fig. 6) where both H. mirabilis and H. retusa occur with occasional hybrids.  Fig. 7 is MBB7818 H. mirabilis Windsor SE Riversdale, where the plants frequently have a frosted appearance because of minute surface spines.

There is a significant geographic jump with fig. 8 MBB7850 H. emelyae north of the Langeberg at Aasvoelvallei. This is a population that I have noted elsewhere that highlights the probable relationship of H. emelyae with the H. retusa turgida and pymaeaoid elements from Herbertsdale eastwards. Fig. 9 is a plant of MBB6666 Tradouw Pass that I recognize as a hybrid population H. mirabilisXretusa.  Inland from there are several populations, MBB7899 is H. mirabilis, Heuningklip (fig. 10) and MBB7896 H. retusa nigra also Heuningklip (fig. 11).  East of that are three populations of H. mirabilis, MBB7912 and MBB7913 Rietkuil and MBB7919 Van Reenens Crest (figs 12 to 14).

As only single plant comparisons, it seems fairly safe to say that, bar flowering time and figs 2 and 3, they are all similar. However, the variability in each of these populations is great and this has been reported elsewhere in the Update volumes. If one had to now take figs 2 and 3 and look for similarities in other populations, it would be very easy to demonstrate a complete gradation from what could be construed as typical H. mirabilis through to typical H. retusa through a large array of populations.

A sequel…Still another view of Haworthia retusa and Haworthia mirabilis.

It has long been my contention that there is no separation between Haworthia retusa and Haworthia turgida. It is one very variable system viz H. retusa, with a larger fairly non-proliferous plants tending to level areas and then smaller proliferous plants on steeper habitats. There is huge variability among members of any one population and of course much more between populations. Over and above this is the relationship of this apparently one single system, with H. mirabilis that is probably even more complex and varied. If one takes all the known populations and variants into consideration it become necessary to ask if H. retusa and H. mirabilis are also not just elements of one system , and one species. If all the considerations are summed and referral is made to vegetation and speciation drivers; what constitutes an area of endemism, then I am sure the answer will be “Yes”! What seems to have happened is a natural sequence. As sampling has progressed so has there been recognition of differences. The logical outcome is that sampling progression should lead to understanding and synthesis by reduction. Unfortunately there will be diehards that stay with the differences syndrome and cannot see the similarities.

Continue reading

Mystery – part 36, Albertinia

A review of the plants photographed recently around Albertinia … I only know of 23 populations in this area that relate in different ways to the names Haworthia turgida, H. retusa, H. mirabilis, H.emelyae, H. pygmaea, H. splendens, H. vincentii, H. acuminata, H. fusca, H. dekenahii, H. argenteo-maculosa, H. pygmaea, and H. esterhuizenii. I still need to get pictures of H. splendens, H. vincentii, and H. turgida on the Wydersriver.

In essence there are two variants – the clumping cliff dwellers (H. turgida) and the mostly solitary flats dwellers (H. retusa). The flat dwellers are far more variable than the cliff dwellers. If all the variation is considered against the differences in each of the habitats, it seems very unreasonable to suggest that these populations are anything but a single species (H. retusa) expressing itself differently according to local dictates and demands. This is same issue of variability occurs in these plants all the way westwards.

97. 2020.03.04 – Esterhuizenii – Aasvoelberg. I was concerned that I am not sure anymore of flowering time because essentially retusa and mirabilis are separated by a late summer vs a spring flowering. None of the populations I saw now in late February showed any sign of buds or flower. Only the Humor plants had just two old inflorescence of about two months age. The fact it is a SYSTEM. The retusa elements are lighter coloured signified by having an element “pallidifolia”, while the mirabilis element has the element “nigra”. Recognising species as systems, variation and differences can be seen in a more realistic way. This does help to overcome the pressures that ignorance, egocentrism, emotion, commercialism and intellectualism bring to bear on classification. H. retusa ‘esterhuizenii’?

The map is useful although it does raise the question of how confidential should we be about locality. Part of this quest was to examine how populations have fared in the years since “discovery” and also in the 50 years since I have been directly involved. My observation is that the main threat is excessive animal pressure – and/or combined with drought. The Aasvoelberg population seems to be very small and a secondary threat is alien weed infestation. But I really do not know the actual size and health of the population. I did see plants further west long ago, but it will be a real mission to explore there properly. An important point about conservation is that it is really only as systems that species can cope with natural and even man-imposed change. It is only with a proper and true definition of the term “species” that we can even discuss them sensibly. “Adaptive” must surely be part of that?

98. 2020.03.05 – This is H. retusa (turgida) at Buisplaas on the Gouritz River between the Gouritz Bridge and Herbertsdale. This form was informally known as H. rodinii and is known from the Gouritz Bridge and also south of that. As a cliff dweller it is normally clumping. The first time I saw such a plant it was a specimen reputed to have come from Die Hell much further north in the Swartberg Mts. VERY unlikely, but H. retusa should be sought in the Gouritspoort where the river passes through the Langeberg Mts. There are many populations of these cliff dwellers and countless variants. I do not and cannot, dispute the fact that names present a problem for suppliers and collectors, but that is not a problem that can be settled by science. Association of a botanical binomial and place is the only solution that makes sense to me. Taking out the geographical detail diminishes the sense of any name. But this series is to explain and expand on this issue.

These are also Buisplaas but in a totally different habitat several hundred meters from the cliff dweller. One picture shows a very proliferous clone. This same juxtaposition of clumping and non-clumping occurs elsewhere and is a pronounced feature of the H. cooperi and H. cymbiformis problem in the Eastern Cape. These Buisplaas populations validate my conviction that the Western cape retusoids are in fact a single species system. There has been a predictive element in all my exploration since the revision of 1999 (Haworthia Revisited) and this population simply fits a pattern. Comparing all the pictures of this series I am now showing will demonstrate this too. H. retusa ‘pygmaea’. I write the name like this because in the absence of a species definition, formal lower ranks have to be meaningless. Furthermore the nature of local variation is such that it is generally impossible to circumscribe ranks. A very good example of this is the persistent reference to H. mirabilis var magnifica which can absolutely not be supported on the basis of a type specimen representing an original group of such similar or like plants.

99. 2020.03.07 – Despite the drought and animal activity (and human predation presumably) – the Cooper Siding plants are in great health. I am posting all my pictures (of Haworthia – there are many other plant species of significance present) because the reality of diversity within populations gets zero attention in citizen science and little more in academia. But do not get me wrong. I write “citizen science” not citizen cognition. Also I do not ignore the fact that “citizen science” also features in academia. These plants (a plant?) was described as H.dekenahii var argenteo-maculosa. In my Handbooks 1976, 1981), I placed the two under H. retusa. Was this wrong? No – because moving them to H. pygmaea as I did in my revision (1999) highlights the reality that this is a single system and not just spatially isolated populations that can be treated as different.

In writing about Albertinia and the conservation state of these Haworthia populations (that really bothers me), some very serious thoughts come to mind. Do we really want to know the problem and the answer(s)? The problem is environmental deterioration – climate change. This is coupled with the decline in moral values across the counter. But do we want to acknowledge this and really want to know what is true. That all of existence is actually a grand illusion that we may choose to be locked in to. I should not have suggested that climate change is the main factor – although Albertinia has been experiencing the worst drought in living memory. Livestock pressure also definitely impacts negatively on vegetation, and our dietary addictions prevent us recognizing this fact.

100. 2020 03.08 – Dekenahii is at Draaihoek on the Valse River northeast of Albertinia. Juxtaposed again on a nearby rocky cliff is “turgida pallidifolia”. A floribunda / chlorocantha variant is in close proximity in its own preferred space. A different form of the turgida retusoid used to be on north facing cliffs a little further north at Weltevrede. Keep in mind that I am considering a bigger picture in which differences within populations negate differences between them, and especially when habitat is considered. I also juggled Dekenahii between retusa and pygmaea and whatever you do with it, the best explanation I can offer as a binomial is H. retusa ‘pygmaea’. Better still is to add the unwritten meaning that it is actually Helgaard Oosthuizen’s discovery of H. retusa as a group of plants at Draaihoek circa 1943 given to Smith by Dekenahii. Names standing alone may be good for business but the interest lies in the information attached to them and which they point to.

This is the “turgida” form of H. retusa at Draaihoek. These plants have more pointed leaves and are more colourful than the “pallidifolia” that I remember 59 years back. But the precise locality may have been different. I remember plants more like those at Tweekuile further east along the river that I will still post pictures of. At Weltevrede further upstream the plants had longer leaves. Steven Molteno coincidentally reminded me of H. marumiana and the exact same conundrum I am trying to explain here, but magnified manifold over the vastness of the Karoo and our ignorance of both marumiana and the Karoo.

101. 2020.03.10 – Tweekuile is north of Albertinia and just a few km east of Draaihoek on the Valse River. This is what H. retusa ‘turgida’ looks like there. It occurs to me that sensible taxonomy, like prevention and cure of disease, is not a sustainable business model 😅

Without any simple and practical measure, how does one deal with an endless array of slightly different looking things affected by age, exposure to direct sun and an also seemingly endless lot of agencies affecting appearance. Compare these two Cooper Siding and Humor pygmeas with the Tweekuile turgidas.

102. 2020.03.11 – Have a good look at the rest of Humor. I suppose it is still fashionable to dismiss variation like this as “hybrid swarm”. Problem here is what parents where and when. To be strictly correct, is there really any option but to say H. retusa ‘pygmaea”?

Mystery – part 37, Albertinia 2

103. 2020.03.11 – Melkhoutfontein. The weird history of “acuminata” is not very flattering. It started with me when I described this as a variety of H. retusa. But I did say some interesting things in 1981 that lead to my present point of view. One is that I said that acuminata may be eventually shown to link H. retusa and H. pygmaea. This is exactly what the present thread is about without any conscious effort to support what I might have predicted. I think I may have changed acuminata to a variety of H. mirabilis in “Haworthia Revisited”? Weird too, but I would not be ashamed. That would reflect the reality – it is one system and countless opinions can be woven around the evidence that supports the idea. The original population of acuminata was destroyed and although I did find plants nearby I did not think such a strong population as this still existed so close by. This population is at Melkhoutfontein on the Gouritz River southeast of Albertinia. The habitat is old river terrace. There were several smaller populations to the north. Coming are populations to the east that inspire further support for the kind of continuities that occur between practically all Haworthia populations.

104. 2020.03.16 – Johnson’s Post plants are also something else. Large clumps on clay pedestals on an ancient river bank? An amazing sight.

105. 2020.03.17 – These plants are at Vleesbaai and I have no doubt that a species name has been coined for them without condemning the need for a name. It is the formal species part that bothers me. From my perspective these are H. retusa ‘pygmaea’. Steven Molteno can give a good habitat description. The conservation aspect is interesting because it is a small rocky area in an expanse of cultivated and heavily stocked lands. The real threat to the plants is the severe stocking pressure and the irony is that grazing is also necessary to keep vegetation under control. I will, I’m sure, come back to the conservation issue.

Steven Molteno – If these are the plants I’m thinking of (they look like it) then they’re all growing on a lone outcrop of quartzitic sandstone of the Skurweberg formation (Ss), Table Mountain Grp. This exposure is a rather eroded ridge very near Vleesbaai, surrounded by a lot of calcrete and alluvium I think.

There’s another (much larger) exposure of this same formation (Ss), not far away to the north. It’s that line of tall hills that runs parallel to the N2, south of the road, and east of Albertinia. Interesting that this larger Skurweberg formation ridge is also home to some unusual mirabiloid-retusoid confluences (the ‘vincentii’ & co. towards the western end of that ridge of hills; pygmaea ‘argenteo-maculosa’ towards its eastern end).

I think this correlation with a specific geological formation is very suggestive of broader connections across this whole Gouritz region.

Soils are very rudimentary on these outcrops. Lithic leptosols, plants growing very close to (or in) bedrock. Eroded grit from quarzitic Skurweberg formation is probably rather acidic, especially with the contribution of broken-down organic material that’s pretty much its only supplement!

Up near Johnson’s Post it’s a completely different story though.

There, the geology is very complex, with lots of funny “slivers” of different formations, all parallel to each other but zig-zagging across the flats.

At Johnson’s Post though, the river’s carved out a series of little kloofs in the terrain. The central valley floor is quite wide and filled with alluvium. The haworthias grow along +-north-facing slopes of Kirkwood formation (Kk). It’s often reddish, but here it’s a light-brown (almost a little ‘greenish’?) siltstone with greyish shales and bit of sandstone sometimes. This is what was called the “variegated marls”, and it erodes into a heavy, fine-grained clayey loam. Very muddy if wet. The same formation (Kk) is the main home for H.pygmaea in the Mossel bay and Brakke regions to the east. There is a bit up near Herbertsdale, and a long strip of it going east-west through Riversdale and Heidelberg. Another patch is just east of Swellendam, and I think there’s probably an exposure at Klaasvoogds but its very eroded. Everywhere except Klaasvoogds, it’s inhabited by the floribunda/chloracantha complex. Sometimes also these funny mirabilis-retusa integrades like near Heidelberg.

To return to Johnson’s Post, above the Kirkwood formation you get this pebbly calcarenite (De Hoopvlei fm I think), but it’s on the flatter area on top and I don’t know of Haworthia there. It’s also mostly ploughed though.

Landtypes at Johnson’s Post are also interesting. Eastern part is Fc15. Fc15-39 are lime-rich river valleys, networking across most of the Overberg, that are always inhabited by retusa ‘turgida’ and by one of the floribundoids. Usually not a mirabilis though.

Western part of Johnson’s Post is landtype Ae133 (obviously these aren’t strict boundaries though, they grade). The south-eastern extremity of the same landtype (Ae133) is where those Haworthia at Vleesbaai live – i.e. Ae133 connects these two populations.

There’s a similar landtype, Ae113, just north of the Breede River mouth (!)

Vegtype at Johnson’s Post is what Jan Vlok calls: Southern Cape Valley Thicket. It’s a thin belt that winds along the Gouritz and its tributaries, with a strip along the lower Goukou too. It nearly always has some sort of toothed-leaved floribundoid/chloracanthoid (along the lower Goukou its H.variegata) as well as H.retusa turgida. The correlation in distribution is quite strong. These haworthias almost seem to trace out this vegtype on the map. I think the correlation with a specific geological formation is very suggestive of broader connections across the whole Gouritz region. These sandstones are very much older than the surrounding sediments. 

Mystery – part 38, Albertinia 3

106 2020.03.18 – This is Paulsfontein just west of Albertinia. A small population in an intensively grazed and weed encroached area. A reminder to keep in mind within and between population variation. This has the Latin epithet ‘fusca’ and I personally fuddle over whether to address it as pygmaea or mirablis. So I suggest H. retusa because these populations simply mirror what I was showing for populations to the west where names like mutica, groenewaldii, badia, joleeniae, bobii, hammeri etc. are collector useful. Conservation is poking me in the ribs but I am not finding the right ambit for that discussion.

A very powerful supporting argument for my thesis of H. retusa as a seemingly massive conglomerate, is the close association with H. floribunda. H. chloracantha, H. parksiana and H. variegata; as well as in the continuities one sees among those ‘species’.

107. 2020.03.19 – I wish I had pictures from my visit to this site about 20 years ago. The place? Lodewykstenk east of Albertinia and east of Aasvoelberg – esterhuizenii. There were many plants. This time I really struggled to find only these 3. Why? Certainly not collectors. Drought and severe animal pressure. The plants have the name H. vincentii. But really. Can you name plants in casual fashion like this without a knowledge of what the name is directed at? A basic life form. I consider that it fits comfortably with all these plants I have been dealing with here.

108. 2020.03.19 – Flat or cliff? What the thesis is that these plants belong in a single gene pool and the enormous variability is due to the demands of habitat as much as anything else. Cliff is vertical rock. A level habitat may have the same rock to soil ratio. Whatever the vast range of non-steep rock sites, most significant is that animals (livestock) cannot graze or trample a vertical rock wall? This is then the cliff hanging form of H. retusa east of Tweekuile, north of Albertinia, but a bit off the Valse River. A fortuitous new record to demonstrate just how much exploration is still needed.

Mystery – part 39, Albertinia 4

109. 2020.03.22 – Soutpankoppies. What is there to do? The Albertinia area is really absorbing. Westwards the gene pool (retusa/mirabilis/turgida/mutica) is confused as it tries to express itself in so many different ways, whereas at Albertinia it simplifies to two and, in my opinion, then one. At the same time there is a second gene pool comprising floribunda/chloracantha/variegata/parksiana. The area is not well explored and there are clearly small islands of vegetation that may still hold some secrets. The photographs here are of ‘splendens’ at Soutpankoppies that I perceive to be the most eastern expression of ‘mirabilis’. Retusa in its typical form ends a little to the west. Further exploration in the Albertinia area will surely expose the facts about these two hypothesized gene pools.

“Splendens”. Not for nothing is it specially protected in an enclosure. But this underlines the real problem of conservation – a huge subject. This particular enclosure is of interest for several reasons. When I first heard of it I assumed it was where the plants were seen in ca 1996. But it is not. So what has happened to that small population? There was also a third ‘population’ in the immediate vicinity of an old small farmstead. Local disturbance and alien weed invasion seem to have annihilated that one. The splendens enclosure is hugely successful in respect of the short term health of the specific population and even satellite imagery demonstrates that. The impact of livestock activity and weed invasion outside of the enclosure are obvious. But the total effect is confounded by the presence of surface rock (ferricrete?). The splendens population would have been as safe in the absence of any fence. The other two populations were far more vulnerable. It is simply not practical to enclose vulnerable ‘species’ and this was a hot topic in professional conservation as far back as 1970 if not before. We cannot ignore the problem of taxonomy, because the essence of conservation is surely the preservation of diversity. At what level now does one do this? The current trend in conservation is the identification of “red-data” species. I think this is complete nonsense because it amounts to plum-picking in which the end-product is the maintenance some kind of museum record of what was?

110. 2020.03.23 – An enthusiast commented that Haworthia magnifica made sense to him. Well here are pictures of plants at the type locality (Riversdale Commonage or now known as the Werner Frehse Reserve) as was indicated to me by the collector of the original material i.e. J. Dekenah. If you want confirmation that the name, as a species name, makes sense it is worth using google to locate the type and see the images that come up. What would be useful is for that enthusiast to set out to demonstrate why this particular name makes sense to him against all the other names that may do the same.

This is probably what H. magnifica is imagined to be, based on my experience with the name, the trade and the literature. But the fact is the population at the Frehse Reserve is substantially fragmented and the plants are highly variable. Not only that, anyone who has seen a retusa/mirabilis hybrid will recognise that influence in the pictures I’ve posted.

111. 2020.03.25 – Here is a set of pictures of plants propagated from seed from a H. mirabilis population (MBB6651) 2km further south from the Frehse Reserve and what was purported to be H. magnifica. The habitat is a bit different because here the plants are in white clay (kaolinite) whereas at Frehse they are in shale. What is common to these plants that makes them different to an impossible to define commonality of H. magnifica???? It is a problem throughout ALL the mirabiloids and retusoids of the Southern cape and extending to the emelyoids of the Karoo. Examine the last picture and you will see the ultimate trickster. The floribundoids (variegata, chloracantha and parksiana) have a show-in too.

The coloration in this plant is what we see in the old ‘mutica var nigra’ population. When one talks of magnifca one cannot dismiss a series of mirabilis populations that occur from Frehse Reserve at Riversdale westwards to Riviersonderend.