11. 2019.5.16 – Where does one go from here? These pictures all date from after the 1999 revision so forgetting all the pictorial information to that date I have only given a peek at what was “turgida”. I still have 5-6 folders for that, 24 for retusa itself and 14 for “nigra”. Then many more for mirabilis, mutica, pygmaea and emelyae. There are 6-8 threads among these that trace various continuities and I think next I will just go via “nigra” on the way to mutica?
What I find extraordinary is the way in which amateur succulent journals resist any effort to rationalise names in accordance with some sort of scientific intent. The Latin binomial seems to be all significant and it has made life in Haworthia absurd. All it needs is a very simple adaptation and the adoption of a convention where the species name is taken as generic and is so understood in the community?
Cohan Fulford: taxonomy is seen as a dirty word by many horticulturists, with what is perceived as constant changes – often to well known and cherished entities – and dissent among taxonomists taken as meaning the whole field is arbitrary.
Bruce Bayer: Yes Cohan and even qualified scientists in other disciplines, including botany, do not actually understand the processes.
True “retusa” is already posted from this same locality on the Duiwenhoks and just across the river is a small form of mirabilis that could involve floribunda! When I first saw a picture of this I speculated that it might prove to be involved with H. mutica. I cannot remember the exact history and why it came to be known as nigra var mutica – but as a matter of interest I quote from the New Haworthia Handbook with reference to mutica and retusa…”if the two species do meet it can be suggested to be in the area between Heidelberg and the lower Breede River”. How true this has proved to be. But no meeting at all – just a dramatic flow.
Cohan Fulford: Every one beautiful! Fascinating to get a glimpse into how the various taxa interact.
Bruce Bayer: Better understood as largely interaction within one taxon? There is or are levels above this doing similar things. Why are taxonomists not examining these weird happenings?
12. 2019.5.17 – Here are more pictures of the potential mutica viz a mirabiloid/retusa with floribunda infused. Between Kransriviermond and Heidelberg.
Steven Molteno: It seems a lot of the complexity arises from repeated radiations and confluences – in certain directions. The directions interest me because the southern cape’s been subject to repeated pulses of arid – wet climate (driven by the ice caps’ cycles apparently). So the suitable “bands” of habitat would’ve moved back and forth over the millennia, inhaling and exhaling Haworthia radiations across the Overberg! Perhaps especially along the river valleys, which sound like plant highways!
Bruce Bayer: Yes – I think one of the strongest points to make is that the model has been that an imagined model based on this sort of thinking has been predictability e.g. the fact that nigra is continuous with mutica.
Irving Navarro: Steven Molteno, I always wondered how bruynsii came to be, it’s yellow roots always amazed me
Bruce Bayer: Irving that IS an interesting observation. Bruynsii may have its origins in or near sordida but yellow in the roots may be an aloid character?
13. 2019.5.17 – There is also a very strong north/south influence in the distribution of the elements. Floribunda is playing a much stronger role in my narrative than I anticipated. It covers virtually the same range as the 6 elements of retusa. But to the east it does not occur south of the principal road from Cape Town to Mossel Bay. It is only at Swellendam where it does come south of that and it emerges from mirabilis as a wholly separate element far further south at the Potberg where it is partly confounded with H. variegata. It has an incredibly close association with the atrofusca forms of the mirabiloids. These here are from 3 populations west of Heidelberg where the preceding muticoid influence is very strong as well as the input from floribunda. As a general comment, the mirabiloids to the west are generally more dominant in the southern parts.
Bob Hunter: Bruce – I am finding this series of posts very.interesting, and am glad that they are going to be collated, edited, and published. I hope that, given the problems with the traditionally used language here, that published collation can in some way accompanied by some sort of ‘graphical’ illustration of these insights – a hard ask, I know, but it would help a lot to make people think more about this issue.
Bruce Bayer: Thank you Bob, there is already a great deal published in HaworthiaUpdates.org as edited by Lawrence Loucka, but the whole issue is bigger than myself and it would be nice to grow it as a community of interested people like yourself. Steven Molteno is addressing a big part of the story and we are going to learn a lot more.
14. 2019.5.17 – I have not pre-planned this narrative of the haworthia species mystery in the belief that there is a natural coherence to it despite the very broken nature of the available evidence. Human habitation and agricultural development have changed the landscape dramatically while exploration itself is not complete. I am finding a flow to the story that comes out of the evidence and not out of personal prejudice. Here I post some pictures for a population a bit south of the previous one. The retusoid and muticoid influence is dropping out and it is changing to mirabiloid dominance with an unquestionable infusion of florabundoid.
The language of “oids” is proving very meaningful and from here I will pick up again on the mirabiloid retusoid and the muticoid mirabiloids. I asked Lawrence to edit into the introduction I bit I wrote about the nature of the plants as they relate to geographic space, geological formation, slope and aspect. But also the question of a spring, as opposed to a late summer – early autumn flowering period being a major driver of diversity of this single species complex.
From the population illustrated, the mirabiloids burst southward and westward right up northward into the Robertson karoo and through the Tradouw Pass into the Little Karoo. From there they extend eastwards and merge into the emelyaeoids as other retusoids spread northward via Tradouw Pass, Garcia Pass, and Gouritz Gorge.
15. 2019.5.19 – Language – I have been and am, using the suffix “-oid” to mean belonging to a group of similar things. So far I have not shown that mirabilis and retusa are the same group of things. In fact I may not have done so for turgida and retusa either and tend to treat this latter as an accepted fact. What I have shown is my perception that a mutica-like group originates from retusa and mirabilis. So muticoid arose from retusoid and mirabiloid. So far my posts are following these groups westwards from the Duiwenhoks river and Heidelberg. My last two posts were mirabiloid with a floribunda infusion and these flower autumn. The next post is a little further west of a retusoid – I will call it muticoid retusoid because it does have a mirabilis infusion and it will lead to mutica. As will another group I will call muticoid mirabilis. Bear in mind that flowering time is important and not always available. These pictures now posted, were taken in September and thus spring flowering.
Incidental but very important is that nearby is one of the few floribunda populations South of the main e/w highway. These elements/oids are not sharing habitat!!