Table of Contents


A new variety of Haworthia Limifolia from Natal (1962)

Reprinted from “The Journal of South African Botany”, vol. XXVIII, part III, July, 1962


M.B.Bayer, College of Agriculture, Cedara.

The typical form of Haworthia limifolia is from somewhere west of Delagoa Bay and was described by Marloth (1908).  Prof. R. H. Compton has kindly sent me specimens from the Umbuluzi River Valley north of Stegi and also a form from near Gollel on the southern border of Swaziland.  Herbarium records show that forms also occur near Barberton;  the confluence of the Pongola and Pivaans River 20 miles east of Paulpietersburg; Ndumu, Zululand;  Kosi Bay, and the Ubombo Mountains in Zululand.  A photograph of a plant collected by Mr. E. R. Harrison 6 miles west of Somkele on the slopes of the Nkonyana Mountains, matches plants collected by me at Ngceba, north of the Black Umfolozi River, between the Umfolozi and Hluhluwe Game Reserves.  This form is also reported to occur on the nTsuzi and Ulumbi hills which flank the Umfolozi Reserve on the north and south.  Two plants have been collected from this area by Mr. H. Dent.  Mr. A. F. Bruyns-Haylett also records it from the Mozaan River Valley between Swaziland and the Pongola River (fig.2.)

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Haworthia as a problem genus (1970)


M.B Bayer, National Botanic Gardens of South Africa, Karoo Garden, Worcester.

Although many enthusiasts have recognized the need for a better understanding of haworthias as they grow in the field, South Africa has been very slow in providing the necessary interest.  Mr. G.G. Smith did a vast amount of work only to withdraw from the field before this work could reach fruition.  As a result, even his contribution has done very little towards solving the fundamental difficulties in the group.   Practically all the errors which can contribute to unsatisfactory classification have been made.  Perhaps the most unfortunate, and the most forgiveable, has been the total failure to recognize the importance of locality and variability.  In other words haworthias have never been studied on a population basis.  This has led to unnatural sections in which only superficial morphological characters have been used, and too many superfluous species and varieties which have no basis as far as the distribution of the plants is concerned.   Floral structure has several times been suggested as a possible solution to the problem of identification, but has never led to any further conclusion.  Why, of course, is very obvious.  To try and establish order from false foundations will never succeed.  The basic premise that the species described are true representatives of morphologically and geographically distinct species has never been questioned for the haworthias.  New species and varieties were freely described by Smith, von Poellnitz and Uitewaal (and Resendé) although the real identities of Haworth’, Salm Dyck’ and Baker’s species were in many cases unknown.

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Variation in Haworthia with particular reference to HAWORTHIA GLAUCA, Baker. (1970)

Written for, and then printed and distributed by Haworthia Study Group, New South Wales – October 1970.

M. B. Bayer, Karoo Garden, Worcester, South Africa.

Much of the confusion in the taxonomy of the genus Haworthia could have been avoided if more attention had been paid to localities and inherent variability of the species.  The tendency has been to base species on single specimens and to regard the species as variable concepts subject to personal opinions.   According to Stebbins in his book “Variation and Evolution in Plants”, a species comprises a system of populations separated from each other by complete or sharp discontinuities in their variation patterns, and this must have a genetic basis.  Therefore there must be isolating mechanisms to prevent transfer of genes. In Haworthia, most (not all) of the species are found in rock formations and stable situations at moderate altitudes, and hence the populations are well spaced.  Haworthias are also insect pollinated, mostly by solitary bees, and as stated by Clausen in “The Evolution of Plant Species”, it is logical that spatial separation of the plant populations coupled with flight limitations of the pollen vectors, will with time have led to differentiation of highly localised populations.  A further problem in Haworthia is that the species do in fact exist at different stages of differentiation.  Thus one may be forced for practical reasons to regard a widely ranging series of varying populations as a single species, simply because the degree of  inter-gradation and variability precludes any other alternative.  If there is an alternative, it is to recognise varieties in the sense that this concept has been used in the past, i.e., to apply to individual variants and forms.

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Changes in the genus Haworthia Duval. (1971)

Printed in Cactus and Succulent Journal (US), 43:157 (1971).

M.B.Bayer, National Botanic Gardens of South Africa, Karoo Garden, Worcester.

The genus Haworthia is sub-divided into twenty sections principally on leaf and growth habit.  The composition of the sections thus often bears little relation to the actual and natural affinities of the constituent species.  Sub-division of the genus on the basis of floral characters has been suggested by Uitewaal (1947) and reference should also be made to Berger (1908).  In Das Pflanzenreich, under the Section Margaritiferae, Berger particularly comments (citing N.E. Brown) on the problem of garden hybrids, and it is unfortunately true that many species are still recognized which have no real basis in field populations.  These inevitably obstruct attempts at presenting natural relationships, and hence also a desired aim of plant classification.  The inadequacies of leaf morphology as a basis for subdivision is particularly evident in a study of the species H. reticulata Haw., H. herbacea (Mill.) Stearn and H. schuldtiana var. maculata vPoelln..  These species are presently placed in the sections Muticae, Arachnoideae, and Retusae respectively, when in fact distribution, inherent variability, field hybridization and floral morphology demonstrate their unquestionable affinity.

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Anguish Among the Haworthias. (1972)

Printed in Cactus and Succulent Journal of Great Britain, 1972.

M. B. Bayer, Karoo Botanic Garden, Worcester, South Africa

Confusion in nomenclature has robbed an attractive and interesting genus of much of its charm and enticement to the collector.  For the past few years considerable effort has been made at the Karoo Botanic Garden at Worcester, South Africa, into the investigation of Haworthia.  It has been disturbing to find the extent to which current nomenclature is at variance with the natural groups as they are found in the field.  Perhaps more disturbing is the difficulty which obviously lies in reducing the complex field relationships to an understandable and usable system of classification, Haworthia can clearly be divided into three subgenera on the basis of floral characters; these are the subgenus Haworthia in which the base of the floret is rounded-triangular and in which the outer three segments completely enclose the three inner ones, and the subgenera Hexangulares Uitewaal and Robustipedunculares  (Uitcw.) Bayer in which the floret base,is rounded-hexangular (the florets stipitate in the former) with the outer floral segments separated by the midribs of the inner segments.

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Natural Variation and Species Delimitation in Haworthia Duval. – Part 1. HAWORTHIA RETICULATA (Haw.) Haworth (1972)

Printed in National Cactus and Succulent Journal, 27:10(1972).
M. B. Bayer, National Botanic Gardens of South Africa, Karoo Gardens, Worcester.

Abstract:  The name Haworthia reticulata (Haw.) Haw. is upheld for a species occurring in close association with H. herhacea (Mill.) Stearn in the Robertson Karoo.  Evidence is presented to show that H. haageana v. Poelln., H. hurlingii v. Poelln. and H. intermedia v. Poelln., together with published varieties of these, have their origin in the same species complex.  These species are reduced to synonymy in the single species H. reticulata.  It is suggested that H. subregularis Baker may also be synonymous.

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Natural Variation and Species Delimitation in Haworthia Duval. – Part 2. HAWORTHIA HERBACEA (Miller) Stearn. (1972)

Printed in National Cactus and Succulent Journal, 27:51(1972).
Part  2. HAWORTHIA HERBACEA (Miller) Stearn.
M. B. Bayer, National Botanic Gardens of South Africa, Karoo Gardens, Worcester.

Abstract:  The application of the name Haworthia herbacea (Mill.) Stearn to field populations is discussed.  It is concluded that this name applies best to the predominant complex occurring in the western and south-western Robertson Karoo.  The species H. aegrota v Poelln., H. submaculata v Poelln., H. luteorosa Uitew. and the variety H. pallida var. paynei are shown to have their origin in the same complex, and are therefore reduced to synonymy.

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Natural Variation and Species Delimitation in Haworthia Duval. – Part 3. HAWORTHIA REINWARDTII Haw. and HAWORTHIA COARCTATA Haw. (1973)

Printed in National Cactus and Succulent Journal, 28:80(1973).
M. B. Bayer, National Botanic Gardens of South Africa, Karoo Gardens, Worcester.

Abstract:  The names Haworthia reinwardtii Haworth and H. coarctata Haw. are upheld for two related species occumng in the Eastern Cape, South Africa.  The species names H. fulva Smith, H. musculina Smith, H. baccata Smith.  H. peacockii Baker and H. coarctatoides Resende et Viveiros are rejected as superfluous.  H. coarctata subsp. adelaidensis (Von Poellnitz) Bayer stat.nov., H. coartata subsp. coarctata var. greenii (Baker) Bayer stat.nov. and H. coarctata subsp. coarctata var. tenuis (Smith) Bayer stat.nov. are the only infra-taxa recognised.  The many varieties of H. reinwardtii previously upheld are, recognised as forms within the two accepted species. A map showing the distribution of the taxa is given.

Introduction:  Considerable doubt most exist that all the varieties of H. reinwardtii Haw. are really necessary.  Unfortunately such doubts are seldom associated with a rationalised expectation of what varietal differences should express.  It has already been shown that problems in Haworthia taxonomy can only be resolved by the adoption of a realistic species concept.  The object of this paper is to report on the field investigation into the distribution and variation of H. reinwardtiii and its allies, with observations on population structure within this complex.

The species involved in this study are all in the Section Coarctatae Berger, and include H. baccata Smith, H. coarctata Haw., H. coarctatoides Res. et Viveiros, H. fulva Smith. H. greenii Baker, H. musculina Smith, H. peacockii Bak., H. reinwardtii and varieties of these.  Apart from Smith’s species, original localities are not recorded.

Investigation:  Attention was confined to the Eastern Cape, in the area extending from Addo in the west to East London in the east, and from the southern sea coast to the Fish River in the north.  As for other species of Haworthia, it was found that plants are nearly always confined in small localised populations of varying densities.  No particular correlation of distribution with vegetation type or geological formation was observed, and plants were recorded from sea-level to 650m through four main vegetation types and three geological systems.  Distribution is primarily associated with rocky, well-drained situations and reduced competition from other vegetation.  This latter point is by no means always true, as for example H. reinwardtii var. tenuis Smith, growing in deep soils under a dense canopy of Valley Bushveld vegetation.  Similarly, as the name implies the origin of H. greenii var. silvicola Smith was also sylvan.  Fifty-three collections were made at different points throughout the area, paying particular attention to localities for recognised varieties where known.  Of these, only H. reinwardtii var. peddiensis Smith was not recollected.  In each case up to ten pieces of full- length leafy stem were collected from separate plants at each site.  Judgement of the taxonomic position is thus based on field impressions, collections made personally by the writer, twelve collections made by Mr F. J. Stayner, 31 single plant collections still extant in Smith’s collection after 30 years, and on herbarium specimens in the Albany Museum, Grahamstown, the Compton Herbarium, Kirstenbosch and the Bolus Herbarium, University of Cape Town.

Attention is drawn to specimens in the Bolus Herbarium; H. Viedge April 1927 from “Tabase’ near Umtata”, a sparsely tubercied and steeply spiralled plant like H. coarctata, R. C. Holmes August 1935 from ‘between Kei and Tsomo Rivers” which is akin to H.. attenuata Haw., and a glabrous leaf remnant, Pillans November 1906, from “between King Williamstown and Grahamstown”.  Neither of the latter specimens can be confidently allied to present known taxa, and the Umtata specimen in particular represents a complete contradiction in terms of the known distribution of the genus.

In the case of H. baccata. a thorough search was made in the Isidenge area of the Stutterheim district before concluding that the locality was a most improbable one.  It was subsequently learned from Mr W. E. Arrnstron (a well-known collector) that the plant had not been collected at Isidenge but in fact came from Frazers Camp near Grahamstossn.  The plant came in Smith’s possession at third-hand and there is thus reason to question the given locality.  Interpretation of observations presented here was subject to particular consideration of both phenotypic and genotypic variation.  Phenotypic variation is the outward appearance of the individual as it responds to factors in the environment.  Comparison of specimens collected from the same sites as plants growing in Smith’s collection showed surprisingly little differences.  Attenuation resulting from shading was seldom encountered and it was nearly always possible to observe plants at each locality in demonstrably steady growth states.  More difficult were certain localities where combinations of rock substrate and shade produced more variable growth conditions.

As far as the genotype – the fixed genetic basis of variability – is concerned, the problem also appears relatively slight, despite the high percentage of polyploidy noted by Riley (1968).  Riley suggested that polyploidy may account for the large number of taxonomic varieties in H. reinwardtii, or alternatively because differences between these are small, that they may have arisen as single gene mutants which have propagated vegetatively.  Riley and Mukurjee (1965) recorded 4 diploids, 8 tetraploids and 1 aneuploid.  These are H. fulva, H. reinwardtii vars. olivacea Smith, tenuis Smith, haworthia Res. (= reinwardtii) with 2n =14; H. baccata, H. musculina, H. greenii var. silvicola, H. reinwardtii vars. huntsdriftensis Smith, valida Smith and an unnamed variety with 2n=28:

and H. greenii forma pseudocoarcata (VP) Res. with 2n=28 and 30.  In 1962 (Riley,1968) these authors also recorded the aneuploid H. reinwardtii var. chalwinii (Marl. et Berg.) Res. with 2n=26.  Resende and Pinto-Lopes (1946) recorded the following: H. reinwardtii vars. adelaidensis VP., triebneri VP, minor Haw. and major Haw. 2n= 14:  H. reinwardtii vars. conspicua VP, fallax VP, haworthia, chalwinii, H. greenii forms greenii, minor and pseudocoarctata 2n =28:  H. reinwardtii var. archibaldiae VP 2N=21;  H. coarctata vars. coarctata, kraussii Res. and coarctatatoides Res. et Viv. nom. nud. 2n=42.

Where these records can be referred to field populations, it appears that diploids and polyploids are encountered across the range of the species complexes.  Thus polyploidy is not conclusively a basis of species or varietal differentiation in this group.  If it were so, one would expect some evidence of discrete sympatric populations – which is definitely not the case for example, at ‘Hopewell’, Bathurst. Here H. fulva, H. musculina and H. greenii var. silvicola all have their origin in the same close locality.  Smith’s field notes, in which he also recorded H. coarctata, H. chalwinii and H. reinwardtii from the same locality, put the three taxa into proper perspective.  Apart from the fact that H. musculina and H. greenii var. silvicola have been cited as tetraploids, as opposed to H. fulva which is diploid, these three taxa do not command separation if indeed recognition at the level of forms. H. coarctatoides is a nomen nudum for a plant said to be intermediate between H. reinwardtii and H. coarctata and can be rejected as a meaningless taxon.

Only one locality was found presenting any real evidence of two non.-interbreeding entities growing together.  This is at Hellspoort where one of these entities is allied to H. coarctata and may thus be hexaploid (or perhaps only tetraploid following Resende’s notes on the locality for H. greenii forma pseudocoartata at Alicedale, a plant which the writer allies with his interpretation of H. coarctata), and the other to H. reinwardtii var. adelaidensis which is diploid.  The latter variety can be shown to be correctly related to H. coartata at subspecies level.  An interesting point is the occurrence of sterile or at least partly sterile triploids in the H. reinwardtii vars. archibaldiae. chalumnensis Smith and peddiensis (Riley, private communication).  The writer particularly noted two populations in which it appeared that despite normal flowering, ovules were aborting.  This does bear on Riley and Majumdar’s (1966) statement that Haworthias usually propagate vegetatively.  While as a general stalement this is incorrect, it is clearly to some extent true for some species including H. reinwardtii and H. coarctata.  Vegetative reproduction could perhaps account for uniformity at different sites if populations had their origins in single clones, or alternatively one would expect more discontinuity where several genotypes were involved.  Variability at various sites and clinal trends across the distribution range, in the writers opinion,  tend to detract from vegetative propagation as a factor in population differentiation.  In support of this comment is the observation on locality restrictions where it is felt that movement of detached stems would surely lead to positive downward migration of populations.  Yet it is a feature of the species, particularly nearer Grahamstown and notwithstanding earlier comments, that they occupy elevated positions on edges of ridges and plateaus.  Nevertheless there is adequate evidence that vegetative propagation does occur especially under conditions of heavy grazing.

A final consideration is the exploratory work done by Riley and Isbell (1963) on paper chromatography in the Aloineae.  Here it was suggested by way of demonstration that H. fulva was close to H. greenii, that H. reinwardtii vars. tenuis. committeesensis Smith and possibly diminuta Smith were close, that H. reinwardtii vars. haworthii and chalwinii were similar, whereas the vars. archibaldiae, valida and H. baccata were different.  If H. baccata had originated at Frazer’s Camp, the chromatograph could have been expected to show affinity to H. reinwardtii var. diminuta.  Similarly on the basis of distribution and outward appearances, one would have expected diminuta to be at variance with, rather than relating to committeesensis and tenuis: the latter two also expectedly differing to some degree.

Results and Discussion:  The superficial impression that might be gained from the field is that a single species complex is involved.  However, three distinct entities, with the two larger of these exhibiting strong clinal trends, are apparent.  The two principal entities are regarded as H. coarctata and H. reinwardtii and it is rather surprising that there is a complete break in continuity between them despite their close affinity.  Conceptions based on past taxonomic treatment give no indication of this discontinuity, and varieties previously described under H. reinwardtii actually belong in H. coarctata as will be shown.  Even the older species H. chalwinii resolves under H. coarctata rather than H. reinwardtii as implemented by Resende.  Most existing taxa in the complex are based on size, density of leaf arrangement and on shape, size and arrangement of leaf tubercles.  That these criteria are inadequate is clear both front examining variability within and between populations. and from the relation of the described taxa to one another and to field populations.

In attempting to rationalise the discontinuity between eastern and western populations in the complex, it was concluded that the general difference as associated with the spiral arrangement of the leaves on the elongated stems – a principle of phyllotaxis elaborated by Church (1904).  (Church postulated that phyllotaxis is a result of fundamental growth processes and can be treated mathematically.)  It is this phenomenon of spiral series which provides the device by which the two entities can be consistently and satisfactorily differentiated.  By cutting the leaves at right-angles near (4mm) to the stem, these spiral rows (parastichies) can be more clearly observed.  In the entity H. coarctata there are apparently 2 spirals ascending in one direction with approximately 4.5 leaves per revolution, while in the reverse direction there are 3 spiral tiers with 7 leaves per revolution.  In the entity H. reinwardtii, 3 spirals with 7 leaves per revolution and 5 counter spirals with 11 leaves per revolution are seen.  In fact, in both entities the leaves are arranged in a single continuous spiral about the stem, so that cutting the leaves too close to the stem precludes the configuration stated here.  In both species, the leaves follow successively at an angle of approximately 137.5 degrees, so that the 22scd leaf in the spiral is again superposed over the first (the orthostichy) through 8 revolutions.  The difference in spiral patterning is thus apparently an artifact which is dependant on a number of variables.  These are: the ratio of stem diameter to leaf width, leaf thickness, degree to which the leaves are amplexicaul. (in effect Church’s ‘bulk ratio’), the degree of compression of the spirals on the stem, and the angles at which the leaves are subtended from the stem.  The ratios of stem diameter to leaf width in H. coarctata and H. reinwardtii are 1:1.7 and 1:1.16 respectively (see table 1).  The real nature of the spiralisation of leaves is shown in diagram I and 2.  In H. coarctata the tiers seen on the cut leaf sections are the 3 tiers of the secondary spiral (P2 on diagram) and the 2 tiers of the primary counter spiral (Cl).  In H. reinwardtii it is the 3 tiers of the secondary spiral and 5 tiers of the secondary counter spiral (C2) which are seen: the primary counter spiral ascending at such a shallow angle that the narrower leaf sections comprising it are taken for the primary spiral.  The angle of ascent of the primary spiral in H. reinwardtii is half that in H. coarctata, and it is interesting to note that the maximum stem length of 26cm observed in the field, was also almost half of the 47cm observed in H. coarctata.

It must be stressed that growing conditions may possibly affect the angles of ascent of the leaf spirals to some degree, so that thicker, fleshier leaves in a specimen of H. reinwardtii may produce a likeness to a specimen of H. coarctata grown under hardy conditions. In the writer’s experience of the plants in the field and under cultivation, the distinction between the two species on this basis is absolute, and it is confidently expected that a statistical evaluation of stem and leaf dimensions will verify this conclusion.  It should be noted that in the section Trifariae. the 3 leaf spirals are the secondary spirals (leaves 1-4-7- . . . ). In Astroloba and Poellnitzia, the 5 spirals are secondary counter spirals (leaves 1-6-11- . . . ).  A plant of H. margaritifera (L.) Duv. at the Karoo Garden has the leaves in 8 spirals – the tertiary spirals (1-9-17- . . .), while even the distichous leaves in H. truncata Schon. are arranged in a spiral series (the primary counter spiral!  The leaves are arranged spirally in all plants and whether the spirals impress visually or not depends on the width and thickness, curvature, nature of attachment, and density of the leaves on the plant stem.

The distribution of the principal entities recognised in the present study is shown in the accompanying map.  In H. coarctata, very large forms exist as populations in the vicinity of Patterson, Alicedale, Hellspoort and Fort Brown.  Intermediate forms occur south and west of Grahamstown. and smaller forms in the Bathurst-Alexandria area.  The Hopewell population is not such an extremely heterogenous one as earlier notes suggest, and localities on the Kowie River at Vaalvlei and at Blaauwkrantz Bridge near Manley Flats display perhaps greater variability.  H. reinwardtii var. tenuis represents a distinct discontinuity and is upheld in the species H. coarctata, in the absence of further known populations, at varietal level.  H. fulva, H. musculina and H. reinwardtii var. committeesensis do not represent marked discontinuities, and the same is true of H. reinwardtii var. chalwinii. The latter appears to be an admittedly rather di€tinctive form, but which appears in various population of H. coarctata including the entity tenuis.  H. greenii at Howiesonspoort is recorded as both tetraploid and aneuploid and is a notable variant although clear population discontinuity does not occur.  Its tetraploid state does not necessarily suggest taxonomic separation from the main body, H. coarcata, where diploid to hexaploid states are known.  H. peacockii with its submersed tubercies is considered to be a local variant at Howiesonspoort and is rejected taxonomicall, while H. greenii is upheld at varietal level only.  With the rejection of H. chalwinii at any level above that of forma, H. coarctatoides receives similar treatment. H. reinwardtii var. conspicua is rejected as a form of H. coarctata as many plants agreeing reasonably with Von. Poellnitz’ description were seen, but not constituting discrete populations.

H. reinwardtii var. huntsdriftensis Smith represents something of an anomaly.  In the Compton Herbarium, Smith 6818A from “n hill at top Hunt’s Drift, last cutting on west side of Fish River” is clearly H. coarctata, as is Smith 7105 – “top Hunt’s Drift, west side”.  Smith 6818 and 68l8B are from “on hill on top of Huntsdrift just before valley before Frazers Camp”, and these may be specimens of H. reinwardtii.  Smith 3849 “west side of Hunt’s Drift” is an isotype and Smith 7106 “top Huntsdrift near Frazers Camp” is very similar.  There is in all cases a lapse of 4-5 years between collection date and herbarium labeling except for Smith 7106, one year.  If Smith’s detailed locality for the variety “in hollow before last hill going up to last gate at top Hunt’s Drift” is correct, then plants collected by the writer at this locality are at variance with the described taxon.  Either this is due to (a) phenotypic changes brought about by cultivation—which is discounted, (b) errors between collection and recording – and there are six herbarium sheets involved, or (c) there is an additional point not located by the writer where H. coarctata is in close proximity to H. reinwardtii.

The question of phenotypic change is rejected as almost without exception herbarium specimens agree with current field collections.  Exceptions are one specimen labelled “25 miles from Port Alfred to Alexandria”, which is the actual distance between these towns; and the specimen agrees with plants of H. reinwardtii collected at a distance of about 5 miles along that road.  Another exception is Smith 7349 labeled “4-5 miles between Riebeek East and Alicedale” which is a blatant misfit, matching rather specimens from the eastern limits of the distribution of H. reinwardtii and Smith 5218, an isotype of H. reinwardtii var. riebeekensis Smith, labelled “4 miles before Riebeek East from Alicedale” whereas in Smith’s field book the locality is recorded “4.5 miles before Riebeek East from Carlisle Bridge”.  These few discrepancies in all the herbarium specimens (263 sheets) do not allow the supposition that either phenotypic change or incorrect labeling are responsible.  Plants which do match Smith’s description occur at Hunt’s Drift on the east bank, and it is likely that they are also found nearer Frazers Camp.  This may prove important in future studies on this group.  H. reinwardtii var. huntsdriftensis is considered to belong to H. coarctata.

H. reinwardtii var. bellula Smith is another anomaly, as a close search of the type locality, and near localities, failed to produce matching specimens.  What very small specimens were seen were taken to be suffering under adverse growth conditions, and the population at this locality falls into a series extending from Bothas Ridge and Queens Road northeast of Grahamstown, to Hellspoort and Riebeek East.  The Queens Road locality is the type locality for H. reinwardtii var. adelaidensis VP as pointed out to Smith by the finder, W. F. Armstrong.  This is one of Von Poellnitz’ unfortunate errors where a locality has been attributed to the collector’s address rather than to actual field origin.  At Hellpoort there is the case of a smaller, densely-leaved entity coexisting with a more typical population of H. coarctata, albeit not precise superimposition of locality. This fact coupled with morphological criteria, is the basis for recognition of the taxon H. coarctata. subspecies adelaidensis, which includes the populations from which the H. reinwardtii vars. bellula and riebeekensis were drawn.  In the latter case, Smith’s field notes were found to be confusing and the site at Willowfountain north of Riebeek East could only be located by cross reference to noted landmarks and two other species recorded from the near vicinity.

Generally in H. coarctata the tubercles are nearly smoothly rounded and smaller than in H. reinwardtii, where they are frequently large and flattened scale- like.  Also in H. coarctata there are more tubercles across the width of the leaf than in H. reinwardtii.  Between Salem and Alexandria, southwest of Grahamstown, there is one particular population of H. coartata with much larger tubercies and also very densely tubercled on the leaf face.  However, this is not clearly discontinuous if other populations are also considered and a new taxon is not proposed.

The distribution of H. reinwardtii can be traced from Kaysers Beach near East London, to a point west of Port Alfred, then northward to Frazers Camp and Coombs and eastward to Peddie.  Local populations appear to some extent more consistent than in H. coarctata but discontinuities are not readily discernible. H. reinwardtii var. major is a form which can be found at several localities, and H. reinwardtii var. chalumnensis is reasonably regarded as one of these.  H. reiiiwardtii vars fallax, valida. kafferdriftensis Smith, pulchra VP and grandicula Smith similarly have no reasonable basis on the grounds of population discontinuities.  The same is true of the var. peddiensis which, in the absence of field material, it was necessary to compare the described taxon and the living type with populations nearer to the Fish River.  H. reinwardtii vars. zebrina Smith and olivacea Smith are distinctive forms in a notably variable population and it cannot be considered that rank above forma is necessary or desirable.  In the case of H. reinwardtii vars.brevicula Smith and diminuta, the taxa are drawn effectively from the same population at Frazers Camp.  If it was necessary to apply an appellation to this fairly extensive population, perhaps the name H. reinwardtii var. minor Baker would be more appropriate at the extreme of a clinal trend in size-reduction from southeast to northwest.

In H. baccata the specimen Smith 3572 (NBG) is an isotype dated July 1944 and agrees reasonably with Smith’s illustration.  Another isotype, Smith 3572 (BOL) dated November 1945 does not agree with the previous specimen, but does conform with specimens from Frazers Camp.  As Armstrong, who knew the collector, Mr McClaren, maintains that H. baccata originated at this locality, the name is rejected as superfluous.  The locality of H. reinwardtii var. archibaldiae is, on the basis of specimens submitted to Smith by Miss G. V. Britten (of the Albany Museum, and a contemporary of Miss E. Archibald), taken to be at the Umtana River east of Wesley in the Peddie district.  Only four clones were located in a brief search at this site and this scarcity may be attributable to it being a sterile triploid.  Smith identified several plants from other localities as this taxon and Von Poellnitz also recorded two localities – the varietal rank is not upheld.

Conclusion:  The separation of H. reinwardtii and H. coarctata on the basis of morphological criteria, also satisfies geographical requirements.  Local populations in each species, and particularly in H. reinwardtii, tend to have distinctive facies but discontinuities between populations are seldom marked.  It is the writer’s opinion that colouration and general condition of the plants, imposed by local environmental conditions contribute greatly to this phenomenon of local ecotypes, obscuring more basic similarities between populations.  A key for separation of varieties, as presented by Von Poellnitz, may have been workable in a collection comprised only of those particular forms, but not as a basis for usefully or consistently distinguishing field collected material.  The diagnoses by which the described varieties of H. reinwardtii were to have been distinguished from one another can often be totally discredited by inherent variability at each point of origin.  It is a basic tenet of taxonomy that all individuals must be referrable to a species.  If lesser ranks are recognised in these species, it is logical to expect that in the same way individuals will all be referable to these categories and the parent species not treated as a repository for all forms which do not conveniently agree with descriptions.

Believing that the present exposition satisfies these requirements, the writer’s concept of H. coarctata and H. reinwardtii is as follows:-

Haworthia coarctata Haworth in Phil. Mag. 44: 301 (1.824).
Aloe coarctata (Haw.) S-D. Monogr. S6, f. 17 (1836-49).
Haworthia chalwinii Marl. et Berg. in Notizblau Berl. Bot. Gart. 4: 247 (1906).
Haworthia reinwardtii var. conspicua VP. in CJ. 5:31 (1936).
H. reinwardtii var. committeesensis Smith in Jl SA. Bot. 9:93 (1943).
H. fulva Smith in 15.4. Jl SA Bot. 9:101(1943).
H. greenii var. silvicola Smith in Jl SA.Bot. 9:103 (1943).
H. reinwardtii var. huntsdriftensis Smith in Jl.S.A. Bot. 10:14 (1944).
H. reinwardtii var. chalwinii (Marl. et Berg.) Resende et Pinto-Lopez in Port. Acta Biol. (B) 2:175 (1946).
H. coarctatoides Res. et Lopez nom. nud. in Port. Ada Dial. (A) 2:175 (1948).
H. musculina Smith in JS.A. Bot. 14:43 (1948).

Plants with fibrous elongate leafy stems from 5 to 47cm long, overall diameter from 2 to 7cm; leaf length from 2.5 to 7.5cm, width from 1.0 to 2.4cm, thickness from 0.2 to 0.8cm;  ratio of stem diameter to leaf width in region of 1: 1.7; leaves ascending- spreading, multifarious incurved, broadly lanceolate to ovate-deltoid, broadly amplexicaul;  back of leaves rounded, slightly keeled above, beset with numerous small rounded tubercles;  face generally flat to concave, seldom tubercled.

Haworthia coarctata subsp. coarctata var. greenii (Baker) Bayer comb. nov. –
H. greenii Baker in Journ. Linn. Soc. 48:202 (1880).
H. peacockii Bak. in Journ. Linn. Soc. 48:202 1880.
Plants with stems up to 15 to 20cm long, overall diameter up to 5cm, tubercles mostly suppressed or absent.

Haworthia coarctata subsp. coarctata var. tenuis (Smith) Bayer comb. nov.
H. reinwardtii var. tenuis Smith in Jl.S.A.Bot. 14 :51 (1948).
Plants with narrow elongate stems up to 44cm. overall diameter 2.5cm, leaves up to 3.2cm long , 1cm wide.

Haworthia coarctata subsp. adelaidensis (VP) Bayer comb. nov.
H. reinwardtii var. adelaidensis VP in Succ. Afr. 3:82 (1943).
H. reinwardtii var. riebeekensis Smith in Jl. SA. Bot. 10:16 (1944).
H. reinwardtii var. bellula Smith in Jl.S.A.Bot. 11:70 (1945).
Plants with stems from 5 to 15cm long, overall diameter up to 3cm, leaf length 2.5 to 3.5cm, width 1.0 to l.lcm, thickness 0.2 to 0.3cm.  Leaves are proportionately longer and narrower than in type, while stems are more elongate and thinner overall than in corresponding specimens of H. reinwardtii.

Haworthia reinwardtii Haworth
Suppl P1. Succ., 57 (1819).
Aloe reinwardtii (Haw.) S-D. Monogr. S6, f16 (1836-49)..
H. baccata Smith in Jl.S.A. Bot. 10:20 (1944).
(Included in synonomy are the varieties of this species described at various times by Von Poellnitz, Smith and Resende which have not been located elsewhere.)

Plants with fibrous elongate leafy stems from 5 to 26cm long, overall diameter from 2.5 to 6cm, leaf length from 2 to 4.5cm. width from 0.7 to 1.5cm. thickness from 0.2 to 0.35cm;  ration of stem diameter to leaf width in region of 1:1.16.  Leaves ascending – spreading multifarious, incurved, lanceolate, narrowly amplexicaul;  back of leaves rounded, slightly keeled above, beset with large flattened scale-like white tubercles generally arranged in transverse rows, face flat, often sparsely tubercled.

(Note: It is proposed to maintain all specimens collected during the course of this investigation at the Karoo Botanic Garden, so that in due course the above classification can be verified or revised.  Floral morphology has not been considered as a source of characters as the similarity or floral structure in the subgenus Hexangulares Uitewaal suggests that a very meticulous, time-consuming study would be required to prove the worth as a taxonomic aid.  It is also suggested that the above arrangement based on vegetative characters may provide a working basis for further investigation in this complex.  For collectors it is suggested that deposed varieties be regarded as formae in the respective species, as there is no doubt that specimens such as ‘zebrina’ and ‘olivacea’ are striking collectors’ pieces.)

Acknowledgement:  The writer gratefully acknowledges the encouragement and assistance received from the Curator of the Karoo Garden, Mr F. J. Stayner, and also the assistance and hospitality of Mr D. A. Timm of Vaalvlei, Grahamstown, during the course of field work.

Literature cited:
Riley, H. P. The Nucleus, Seminar on Chromosomes (1968).
Riley,.H. P. and Mukurjee, D. The Nucleus 8:2 p. 149 (1965).
Riley, H. P. and Majumdar, S. K. Botanical Gazette 127:4 p. 239 (1966).
Resende and Pinto-Lopez, I. Port. Acta. Biol. (B) 2:178 (1946).

Fig. 1 Photograph of principal entities to show secondary spirals:- Left: KG 31/64 H. coarctata subsp. coarctata. Biaaukrantz Centre: KG 39/65 H. coarctata subsp. adelaidensis. Queens Road Right: GGS 7346 H. reinwardtii. east of Fish River
Fig. 1 Photograph of principal entities to show secondary spirals:-
Left: KG 31/64 H. coarctata subsp. coarctata. Biaaukrantz
Centre: KG 39/65 H. coarctata subsp. adelaidensis. Queens Road
Right: GGS 7346 H. reinwardtii. east of Fish River
Diagram 1. Diagram showing the different angles of the leaf spirals in (A) H. reinwardtii where the low angle of the secondary counter spiral approximates that of the primary spiral in (B) H. coarctata.
Diagram 1. Diagram showing the different angles of the leaf spirals in (A) H. reinwardtii where the low angle of the secondary counter spiral approximates that of the primary spiral in (B) H. coarctata.
Diagram 2. Diagram showing the position of the leaves relative to the stem axis and the spirals so formed. P2 - One of three secondary spirals Cl - One of two primary counter spirals 		C2 - One of five secondary counter spirals
Diagram 2. Diagram showing the position of the leaves relative to the stem axis and the spirals so formed.
P2 – One of three secondary spirals
Cl – One of two primary counter spirals
C2 – One of five secondary counter spirals
Diagram 3. Map showing the distribution of:- C - H. coarctata subspp. coarctata var coarctata Haw. CG - H. coarctata subspp. coarctata var greenii (Bak.) Bayer. CT - H. coartata subspp. coarctata var tenuis (Smith) Bayer. CA - H. coarctata subspp. adelaidensis (V Podia.) Bayer. R - H. reinwardtii Haw.
Diagram 3. Map showing the distribution of:-
C – H. coarctata subspp. coarctata var coarctata Haw.
CG – H. coarctata subspp. coarctata var greenii (Bak.) Bayer.
CT – H. coartata subspp. coarctata var tenuis (Smith) Bayer.
CA – H. coarctata subspp. adelaidensis (V Podia.) Bayer.
R – H. reinwardtii Haw.

Table 1.

Leaf spirals in Haworthia. (1973)

Printed in Aloe 11:31 (1973).
M. B. Bayer, Karoo Botanic Garden, Worcester.

The fascination of haworthia lies in the shape, arrangement, compact neatness and marking of the leaves.  With nearly 170 named species and over 200 varieties, the genus is unfortunately very confused as far as the application of these names is concerned.  Many of the species originally described by Haworth and Baker have not been recognised since, while in recent times new species have been described with little or no reference to occurrence, distribution and variation of existing or related species.  Obstacles in the way of better classification and recognition of the species are many, and include insufficient information on basic morphology.  Secondly, whatever morphological differences there might be between species are often difficult to rationalise and describe, and may even be difficult to perceive with the naked eye anyway.  A third difficulty is the whole question of framing an adequate species concept, or for that matter, a concept of sections.   There is at present even an illogical trend to ‘lump’ the genera Astroloba, Poellnitzia and Chortolirion, into Haworthia, showing that concepts at that level have not reached reasonable finality.  The removal of genera can be applauded for its broadmindedness, if singular lack of appreciation of (a) the criteria by which they can be recognised, or (b) the reasons why they were erected in the first place.  Such an approach must naturally descend to species level, and at a time when the birth pangs of ‘splitting’ and consolidation have barely started, can only lead to a loss of information.

The writer’s experience of the naming of Haworthias and also of other succulent plants, suggests strongly that species descriptions based on broad external appearances are often very inadequate.  Growing conditions including the influence of soil types, temperature, water and light may have such a strong influence on plant growth as to completely nullify the written description, particularly where based on single specimens as has so often been the case.  The object of this article is to discuss the leaf arrangement in Haworthia and its relationship to the general appearance of the plants.  As in many plants, the leaves are produced consecutively at the growing point of the plant, and are consequently arranged in a single continuous spiral about the stem (the genetic spiral).  Thus Aloe polyphylla is by no means unique with its leaf spirals.  When the leaf bases are wide and enfold the stem it is much easier to observe this spiralisation, but when narrowly attached on a broad stem it may be more difficult to detect.  Generally the leaf bases are not continuous as they are in A. broomii where the leaves may be detached from the plant in a long continuous ribbon.  The leaves are produced at a fairly constant angle subtended from the stem and the result is similar to that obtained say when an orchard is planted with the trees at equal distances in and between the rows – i.e. secondary rows are visible when the orchard is viewed from a different angle.   These secondary rows are called parastichies.  The very obvious 3- and 5-tier arrangement of the leaves in the Haworthia section Trifariae and in Astroloba are the result of secondary spiralisation and have long been recognised in taxonomy.  Similarly Haworthia retusa was originally defined as quinquefarious and H. truncata has always been distinguished by its distichous leaf arrangement.

Generally it seems in Haworthia that the twenty-second leaf is again approximately superposed over the first after 8 complete revolutions of the genetic spiral (leaf-divergence (8.360)/21=137 degrees).  However, in the Trifariae only three leaves are clearly visible when the plant is viewed from below and these leaves form the bases of the three secondary spirals which characterise the group.  The leaves are arranged in three tiers with the leaf sequences 1—4—7—10;

2—5—8—11; 3—6—9—12 (i.e. three parastichies).  The classic example of this trifarious arrangement is H. viscosa where every third leaf is superposed approximately over the first.  In the quinquefarious (5-tiered) spiral, the leaf sequence is 1—6—11—16; 2—7—12—17; 3—8—13—18; 4-9—14—19; 5—10—15—20 (five parastichies as in Astroloba), and in the octafarious 8-tiered) spiral 1—9—17—25; 2—10—18—26; 3—11 etc.

In long-stemmed species particularly, it is possible to see simultaneously the arrangement of leaves in tri-, quinque- or octafarious series e.g. in H. reinwardtiii and H. coarctata.  In the short-stemmed, broad- and few-leaved species such as H. retusa or H. pilifera (now H. cooperi), only the lower series are visible, whereas in the acaulescent, many-leaved species, the higher series may appear.  It may seem that the angle of divergence of the leaves from one plant of a species to another is a constant one.  This is not true for the writer has seen for example a single plant of H. rnargaritifera now (H. pumila) with 8 perfect vertical rows indicating a leaf-angle of 135°.  Normally in this species the parastichies 5 and 8 are seen ascending in opposite directions.  In H. tuberculata (now H. scabra) the leaves appear randomly arranged at some localities whereas at others the plants are either trifarious or both the 3 and 5 parastichies are apparent.  In H. viscosa one would expect that to achieve three near vertical leaf tiers, that the angle of leaf divergence must be 120°.  Actually the angles prove to be only complementary, being often on the order 135°, 115°, 110° – to the point that they can be accurately measured.  Similarly in a plant of H. sordida the angles were measured at 180°, 95°, 85°.  Despite the fact that no one angle is measurably the same as the next, the plants still age to maintain an orderly progession of leaves.  In H. truncata, which is distichous (and really only approximately so), the two rows of leaves are actually the consequence of a spiral arrangement in which the leaf angle is near to 180°.

In H. limifolia the average leaf angle is in the vicinity of 160° but this is by no means constant as Diagram 1 of the variety ubomboensis will show.  Some leaf pairs are almost opposed at 180° and the youngest 7 leaves have an average divergence of 170°.  What is perhaps important is that two parastichies are prominent – the primary counter spirals with the leaf sequences 1—3—5—7; 2—4—6—8.  The impossibility of accurately estimating the central axis in the plant from which to measure the angles of divergence must be stressed.  By counting the number of leaves in rotational sequence until a leaf directly above the first is reached, an estimate can be made; thus the ninth leaf above the first in 3 revolutions is the consequence of (3.360)/8= 135 degrees divergence.  Spiral patterning is also related to stem diameter in proportion to leaf thickness and width.  If the stem diameter is great and leaf width small then the higher parastichies will appear.  The relation of stem length to number and size of leaves will also affect spirals.  In H. reinwardtiii and H. coarctata, a complex notorious for its many varieties and forms, the two species with their discrete distribution ranges are separable almost only by the fact that the ratio of number of leaves to stem length differs.  Thus in H. reinwardtii the leaves are more densely compressed on the stem, there are more leaves per unit stem length and the angle of ascent of the genetic spiral is approximately half that in H. coarctata.  Oddly enough the longest stems observed in a recent field study were H. reinwardtii:  27 cm and H. coaretata: 49 cm.  An associated variable is the ratio of stem diameter to leaf width…1:1,7 in H. coarctata, and 1:1,16 in H. reinvardtii.

Diagram 1 illustrates the leaf arrangement in a single plant of H. limfolia var ubomboensis showing the two counter spirals very clearly.  Diagram 2 illustrates the situation in which a uniform leaf angle of 135° presents 8 vertical parastichies, and also how variations of 1—4° alter the entire conformation in only 3 revolutions of the genetic spiral.  At 139° five parastichies are becoming prominent which will reach the vertical at 144°, whereas at 131 °three parastichies will be dominant and reaching vertical at 120°.  A 1°  increase in leaf divergence will result in an 8° displacement at the ninth leaf.

A.H.Church in a fascinating book… “On the relation of phyllotaxis to mechanical laws” (1904), explains that there is a fundamental constant which determines leaf arrangements and spiralisation.  He defines this as the “bulk-ratio”, which is the ratio of the diameter of the leaf buds to the diameter of the stem at the point at which they are joined to it.  In this light, raw dimensions (especially from single plants) can be seen as only a fractional contribution to species descriptions.  Where even normal standards of biometry have been ignored it is even more important to appeal for a more realistic use of measurements.  While proportionate dimensions of leaves and stem (ratios between leaf width, leaf thickness and stem diameter, for example) may help to better describe a species, it does not mean that the basic problem of defining the species will be solved.  In Haworthia the populations are so localised and often so variable that recourse will have to be made to even more refined methods before a satisfactory species concept will be obtained.  It is unlikely that “bulk-ratio” will help solve any problems at species level, but there is no doubt that it can contribute to deciding limits of sections, subgenera and even genera. In the case of the two very closely related species H. maughanii and H. truncata, it would be very interesting to know why the leaves of the former species “spiral” and why in H. truncata they remain distichous.


Diagram 1. Leaf arrangement in Haworthia limifolia var. ubomboensis showing the two primary counter spirals.

Diagram 1. Leaf arrangement in Haworthia limifolia var. ubomboensis showing the two primary counter spirals.

Diagram 2. Representation of leaves diverging at an angle of 135° in which 8 leaf tiers are vertical and a 4° increase or decrease in leaf divergence to show the appearance of 5 and 3 parastichies respectively.

Diagram 2. Representation of leaves diverging at an angle of 135° in which 8 leaf tiers are vertical and a 4° increase or decrease in leaf divergence to show the appearance of 5 and 3 parastichies respectively.


Haworthias – small relatives of Aloe (1974)

Printed in Excelsa 4:17 (1974)


There are few succulent collections which do not include haworthias, although these small and insignificantly flowered plants are not good garden subjects.  Their size, and shade and shelter requirements make them better suited to intensive cultivation in raised containers under shelter.  Very popular with collectors especially prior to World War II, the decline in popularity can be attributed to various factors.  Although the genus is credited with some 160 species and more than 250 varieties, it is highly unlikely that more than 90 species and perhaps 10 sub-species would survive a critical revision.  Many species have been eliminated in recent years, but there are still many maintained only by the mystery of their origin.  Hybrids and ill-defined or inadequate species account for many superfluous names.  The result is an artificial pseudo-scientific system of nomenclature in which the classic binomial system is prostituted for a series of horticultural cultivars.

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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 mirabilis Haworth. (1977)

Printed in Excelsa 7::37 (1977).

Haworthia mirabilis was described by Haworth in 1804 from plants said to have been brought to England by the collector Francis Masson.  It could thus have originated from practically anywhere in the southern and south-western Cape.  Haworth referred to this species as the ‘rough cushion cushion’, and it was characterised by having retuse-deltoid leaves with ciliate-spinose margins and keels, the leaves being smooth on the face and the back surfaces almost tubercled and indistinctly reticulate.  There is no extant type specimen and only the brief original description, and illustrations in Curtis’ Botanical Magazine (t 1354, 1811) and in Salm-Dyck’s Aloe Monograph (s9, t 1, 1836-49) serve to identify and typify the species.

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Natural Variation and Species Delimitation in Haworthia Duval. – Part 4. HAWORTHIA EMELYAE von Poelln. and a new variety. (1979)

Printed in National Cactus and Succulent Journal, 34:28 (1979).
Part 4: HAWORTHIA EMELYAE von Poelln. and a new variety.
M. B. Bayer, National Botanic Gardens of South Africa, Karoo Gardens, Worcester.

The retention of the name H. emelyae v. Poelln. over H. picta v. Poelln. and H. correcta v. Poelln. is discussed.  There is also a discussion of the relationship of H. emelyae to H. comptoniana Smith. to H. springbokvlakensis Scott and to H. magnifica var. major (Smith) Bayer.  A new variety, H. emelyae var. multifolia is described.

Haworthia emelyae was described by von Poellnitz in 1937 and named in honour of Mrs Emely Ferguson whom von Poellnitz presumed to have been the collector.  Von Poellnitz related his new species to H. willowmorensis v. Poelln., to H. ryderiana v. Poelin. and to H. whitesloaneana V. Poelln..  None of these names is currently upheld (see Haworthia Handbook. Bayer, 1976) and it would be extremely difficult to form a picture of H. emelyae from any vision conjured up from the little tangible evidence associated with them.  Similarly the variety H. emelyae var. beukmannii v. Poelln. is known to be a variant of H. mirabilis Haw. (see Bayer, Excelsa 7: 37, 1977) and offers no solution to the problem.  There are three photographs supposedly of H. emelyae in the H. G. Fourcade photographic record of Major F. R. Long’s collection.  This record was compiled in 1940 and one would have expected less discrepancy at this distance in time than the three photographs actually project.  One photograph is of a plant sent in by a collector and recorded…”from the Gamka river, Calitzdorp”.  The plant is obviously H. turgida and comparable with the forms of that species from along the lower tributaries of the Gamka River (which actually becomes the Gouritz River after its confluence with the Olifants River in the Rooiberge to the north-east of Vanwyksdorp).  The second photograph is of a plant in the collection of W. R. van Ryneveld which is also clearly H. turgida comparable with the Lower Gouritz and Mossel Bay forms.  The third photograph is of a plant recorded as from Mrs E. Ferguson herself and this is unmistakably H. reticulata Haw.

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A Story of Haworthia Nitidula v. Poell. ( = H. mirabilis Haw.) (1980)

Previously published Cact S.Jl 52.1 1980
M. B. Bayer, Karoo Botanic Garden, National Botanic Gardens of South Africa

Haworthia nitidula was described by von Poellnitz in Desert Plant Life (11:192, 1939) from plants collected by Major H. Venter.  Venter was very generous with his localities and like most of his others, this no. 15 was also simply cited… “in the environs of Worcester, Swellendam, Caledon and Bredasdorp”.  This is an ideal example for demonstrating the problems of identification of haworthias and especially in the section Retusae Haworth.  J.R.Brown illustrated H. nitidula in the Cactus and Succulent Journal (18:89, 1946) but apart from this and the original illustration accompanying the description, the plant has not figured in the succulent literature.  In G.G.Smith’s records, the species and nine varieties are distinguished.  The interesting thing is that these varieties are drawn from three geographically separated species.  The object of this article is to present Smith’s photographs and notes of his “varieties” and discuss their actual position as they relate to distribution.

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Looking for Haworthias (1980)

Printed in Calandrimia, Succulent Publication, South Australia. :57 (1980).
M.B. Bayer, Worcester, South Africa

The attraction of Haworthias is their interesting diversity of leaf arrangement and form, as their flowers certainly do not attract attention.  My own interest in these plants owes itself certainly to my introduction to a plant then known as Haworthia chalwinii.  This is now know to be a variation of H coarctata in which the leaves are shorter and more closely adpressed to the stem than is normal.  Even now I am still impressed by the closely-incurved, tubercled leaves packed tightly above one another on a stem which may he up to 20 cm long.  Although I was scarcely 10 years old then, the memory of dense mats of H. cymbiformis on a riverine rock-face in the eastern Cape is still a strong one, but interest remained dominant until nearly twelve years later.  My father was stationed in the Natal Midlands and an uncle, who was a Health Inspector in the malaria areas of northern Natal, brought in an Haworthia from those parts.  J. R. Brown’s book…”Succulents for the Amateur” was one of my favourite books and by that stage would fall open at the section on Haworthias.  The picture of H. bolusii most impressed me and I felt that I knew enough then to recognise these plants from Natal as something new.  They seemed to me quite unlike H. limifolia which 1 knew from illustration, and I thought they should be described as a new species particularly to record the occurrence of the species in Natal.  Fortunately Dr. R.A.Dyer, Chief of the National Herbarium in Pretoria, persuaded me to be more moderate and the plant was eventually described as H. limifolia var gigantea.  . Dr. Dyer also suggested that it would be wise to investigate the species in the field and so launched a 5,000 km wild-goose chase across northern Natal, Zululand and Swaziland.  The only direct success my companion and I had was in meeting Captain D. R. Keith at Stegi on the eastern border of Swaziland.  He directed us to the bottom of the Umbuluzi Valley where we found H. limifolia growing in vast quantity on the shaded dry forest floor (On reflection I wonder why he did not direct us to his original farm Ravelston where the vars keithii and ubomboensis were found).   Although we found no other plants, we did find evidence of plants from as far afield as Paulpietersburg. Barberton, Gollell, Mozaan, Hluhluwe and even as far south as Stanger.  The plant is used by native witch-doctors and herbalists as a remedy for a variety of ailments and one recorded use is for the plants to be placed on the tops of the huts as a lightning deterrent.  Our collecting trip was thus highlighted by endless cross-examination of the rural blacks crying to locate where the plants could be found.  Neither of us had more than a smattering of the Zulu language and this was probably our main stumbling block to success.  On one occasion we were excitedly directed towards an unlikely looking hillside to find a police contingent waiting for us on our return to the vehicle.  Our ‘guide’ had taken us for communist agitators.  Another highlight was being marooned in the Umfolozi Game Reserve by flooded rivers.  Taking adantage of the forced respite, we thought we would explore the Reserve itself, famous as the then last resort of the white rhinoceros.  Our intrepid guide directed us off on a side road in search of the hotter-tempered black rhinoceros and we were soon axle-deep in thick black sticky mud.  The guide was most reluctant to get out of the car and help dig, push and curse while we tried to extract it from the mire.

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Natural Variation and Species Delimitation in Haworthia Duval. – Part 5. HAWORTHIA ANGUSTIFOLIA Haworth. (1981)

Printed in National Cactus and Succulent Journal, 37:31(1981).
M. B. Bayer, National Botanic Gardens of South Africa, Karoo Gardens, Worcester.

Haworthia angustifolia was described by Haworth in Philosophical Magazine in 1825 as follows:- “(slender leaved) leaves lorate attenuate, curved, widely recurved, wholly green, apex nearly keeled, keel armed with small closely spaced teeth from point of emergence.  Similar to H. chloracantha Haw., but smaller, leaves narrower, more recurved and longer, 3-4 inches long, convex below, flat above, soft elevated longitudinal lines in the middle, marginal teeth small and barely visible to the eye”.

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Observations on the G. G. Smith Collection of Haworthia. (1982)

Printed  in National Cactus and Succulent Journal 37:105(1982).

G.G.Smith’s collection of Haworthia was donated to Kirstenbosch and the Compton Herbarium in 1950, together with an ostensible manuscript of a monograph, his basic collecting record, various catalogues of literature and odd notes.  However, there was no indication of Smith’s overall view on the classification of Haworthia, or of any intention he had for the genus at the time he abandoned work on it.  On his death in February 1976, Dr M. Courtenay-Latimer obtained many remaining papers from his home, and also the Compton Herbarium became the repository on permanent loan of the entire collection belonging to the East London Museum.  Among the papers are an immense number of detailed drawings by Dr Courteney-Latimer of the kind which were used to illustrate Smith’s publications, as well as very detailed assessments of ‘species’.  Smith accessioned all his plants individually and each plant was assessed on virtually every measurable character.  It appears that Smith first considered whether a new taxon was indicated or not, and then made these numerical assessments against plants which either were, or were considered to be, existing taxa.

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Haworthia – Confusion Reigns Again (1986)

Printed in Excelsa 12:91 (1986)

Haworthia is a genus plagued by confusion of one kind or another and it seems now impossible to write about these plants without casting doubts on someone’s integrity or sanity.  The problem in the genus is not simply that there are very few herbarium specimens, or adequate descriptions and illustrations by which the various species can be typified. The various elements in the field are so continuously variable that it is difficult to decide where one species begins and another ends – but not so difficult.  There is some straightforward confusion as in the case of Haworthia margaritifera (L.)Haw. where Wijnands shows that H. pumila (L.)Duval is incorrect.  (Excuse my nomenclature – but this means it is incorrect for the species to which Duval attached the name [H. herbacea] – it is correct for the species to which Scott attached the name).

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Haworthia and Nomenclatural Confusion (1987)

Printed in British Cactus and Succulent Journal 4:45 (1987).

Haworthia is indeed a popular genus which seems to inspire a great deal of controversy and confusion.  One would have to be very thick-skinned to be able to ignore past history and not plead for forgiveness for similar transgression.  I was just busy trying to clarify, in my own clouded mind, the problem of H. pumila (L.) Duval, when I saw Will Tjaden’s little article on the subject in this journal (3:88, 1985).  Gordon Rowley in the same issue reviews the recent books on Haworthia and also mentions the H. pumila versus H. margaritifera debate.  Coming so soon on the heels of Fearn versus Cole and Walker versus Bruyns, it would be insensible for Bayer to take up the cudgels against anyone.

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Natural Variation and Species Delimitation in Haworthia Duval. – Part 6. HAWORTHIA MACULATA (V. Poelln.) Bayer. (1987)

Printed in British Cactus and Succulent Journal 5:13 (1987)
Part 6. HAWORTHIA MACULATA (V. Poelln.) Bayer.
M. B. Bayer, National Botanic Gardens of South Africa, Karoo Gardens, Worcester.

Haworthia maculata (V. Poelln.) Bayer. Haworthia Handbook: 130 (1976);  New Haworthia Handbook: 43 (1982);  J. W. Pilbeam, Haworthia and Astroloba: 89 (1983).  H. schuldtiana var. maculata v. Poelin. in Feddes Repert. Spec. Nov. 49: 25 (1940).  Type: Cape; in the neighbourhood of Worcester, Swellendam, Bredasdorp and Caledon. Major H. Venter No. 6a. No specimen preserved.  Neotype: Cape- 3319 (Worcester): Worcester District, H. Venter No. 6a in G. G. Smith 3912 (NBG)

scans 005

Rosette stemless, 30-70mm in diameter, up to 60 leaves.  Stem thick, white-fleshed, non-fibrous, 1/3 diameter of rosette, never elongate, slowly proliferous from base.  Roots thick, white-fleshed, non-fibrous.  Leaves erect, spreading, slightly incurved at tips, up to 60mm long, 12mm broad, 8mm thick, ovate-lanceolate acuminate, aristate with bristle up to 5mm long, seldom setiferous, green to grey-green, purplish- green in sun, lines distinct with pronounced small longitudinal transparent areas on upper surface, lower surface heavily mottled or with longitudinal markings, spots occasionally with small hairs, face slightly concave at base, convex-turgid towards upper 1/4, back convex, frequently with second keel or with double row of spines on keel, margins sub-acute, lightly spined, spines white, up to 0.5mm long to 1mm apart.  Perianth white, yellowish-green inside, nerves pinkish-brown outside, pinkish inside at tips, tube ascending curved, up to 16mm long, obclavate, bluntly triangular at base, 4.5mm across reducing to 3mm, segments free, regularly stellate, inner lower segments incurved along upper margin.  Buds biarcuate, bifid at tips.  Flowering Oct-Dec.

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Haworthia History – Zurich (1997)


The history of this succulent genus is an interesting one as it has its roots in the earliest botanical exploration of the Cape.  Haworthia were included in the first collections of plants when the main concern of botanical collections was medicinal and culinary use of plants.  Haworthia were depicted by several different artists in the late 17th and early 18th century.  These early illustrations were surprisingly good and can be interpreted according to present understanding.  The fact that they have been the object of much confusion is really attributable to the inherent difficulty in understanding the genus and its component species, rather than to poor quality of the illustration.

The genus is not easily separated into separate and easily distinguishable species and the history is correspondingly confused.  Although there are some earlier illustrations, it is the illustrations in Caspar Commelin’s ‘Horti Medici Amstelodamensis in 1701 that form the basis of the taxonomic record.

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Fundamentals as I see them (1997)

I commented rather defensively, harshly and disparagingly on Ingo Breuer’s article in Haworthiad 10:1, and now here is Haworthiad 10.2 with the second part.  There are also three good letters responding to my request for comment on the requirements for another handbook.

In my frustration with the other authors who also write about Haworthia, it has become obvious to me that I have to look at my own motive and what reward I seek.  H. Jacobsen wrote an article (C&SJ(US) 46:230, 1974) entitled ‘Why I wrote books’, but it disappointed me as I do not think he addressed the issue very well.  He cited talent as one motive for writing and, as a second and only alternative, the professional scientist writing in pursuit of his own perfection.  I do not think that either of these are correct.

It is generally acknowledged that in life we try to create an impression.  Calvin (of Calvin and Hobbs) put it ‘God put me on earth to accomplish a certain number of things..’.  Here we have two other views.  Surely another is simply to earn a living, and there are probably more.

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