Kaboega

Kaboega is located in the Zuurberg Mountains north of Port Elizabeth in the Eastern Cape province of South Africa. Read more about this in Haworthia Update Volume 1, Chapter 5:- The Haworthias of Kaboega. There are a mind-boggling array of Haworthia populations here in an area considered to be the meeting point of several vegetation biomes. There is much exposed rock, and the soil is very skeletal, composed of three major groups: sandstone, mudstone, and glacial deposits. These pictures are of a Haworthia cooperi variant that occurs high up on sandstone. I went to this spot because researchers had sent me a picture of a cycad festooned with Haworthia. I did not get to the exact spot but have seen the way it forms hanging bundles in other situations.

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Haworthia glauca!! can also be found here. On Kaboega these plants often have a very close resemblance to H. coarctata and it is no co-incidence that the distributions of these two species complement each other. An essential element of species recognition is their juxtaposition and if they occur in very close association or not. Darwin said as much.

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I visited four populations of this greenish cooperi. One can find plants like this from east of Grahamstown right through to the Little Karoo. Here they are on Dwyka (glacial) skeletal soil.

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These next are in the shales low down in the valley on Kaboega – I name it H. aristata. It is very common in the area but complements H. cooperi while there are populations that are neither. Populations cannot be treated in isolation and there is a distinct possibility/probability that I have been too generous with species. The attempts to find answers via DNA sequencing should make the vendors of that technology thoroughly ashamed.

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More of these green things. I would guess that these would class as the simple progenitors of cymbiformis and cooperi. Perhaps even of mucronata?

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This is Haworthiopsis sordida that does not occur, as far as I know, north of this. H. nigra also occurs here at it’s most southern at this longitude. Altogether it is quite a complex network of distribution patterns that relate to greater plant geography.

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From another population as variants on a theme. have seen about 30 such just on this small mountain area and it just suggests what is still unseen on the length and breadth.

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Not a great diagram but a way to appreciate the drammatic choreography of plant distribution and how it impacts on classification. Without it Haworthia names make no sense other than as imagined and fantasized. Cooperi and cymbiformis occur as intertwined species to the east and south. In the south they extend westwards to get lost in H. mucronata. Cymbiformis as an independent species does not enter Kaboega except as an observable variant of H. cooperi. The cooperi gets lost westwards as variants of H. decipiens. Perhaps close northwards as H. aristata. H. glauca does cross the Zuurberg but is here confused with H. coarctata that may occur in recognosable form on the eastern tip. Angustifolia is on the eastern end too but does not enter Kaboega. Neither do H. monticola or H. zantneriana from the west. This is also closely tied to the intrigue of winter vs summer rainfall and still further to the massive geological changes of the very recent..

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Zuurberg

What do you think this is?

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Incidentally both the soft shale bands within the Sandstone strata as well as the Bokkeveld Shale above, decompose to kaolinic clay.

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I took so many pictures that I will just post because I was so fascinated myself. The population is in an area quite new to me and wholly empty as far as haworthia records go – but perfectly predictable if you throw out the chaff. In the meantime, keep thinking.

The plants were all in much the same situations among sparse restioids and grass and very few other succulents. Next I will post better pictures of a few plants and explain a bit more.

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What do we have so far? Mirabilis, ‘magnifica’, atrofusca, pygmaea, comptoniana, esterhuizenii, Quite good actually – but some serious omissions. Any more offers – these are all excellent.

Just to make sure the name “magnifica” makes sense, here are a few pictures taken at the type locality.

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While looking at those magnifica pictures I was struck by these two to show how a retusa influence is present.

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A closer look at the new find.

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The scenery

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Those flat top hills are the remnants of an ancient african plateaus prominent from near Barrydale to beyond Uniondale – north of the Langeberg. – silcrete upper layer like the concreted layers also present topping the inselbergs south of the Langeberg.

So what is it? If H. magnifica makes sense to anyone as a species, that person is lost to me. This new population is in the sequence from Muiskraal eastwards and it is H. emelyae (‘breueri’, ‘wimii’). The identifications put forward are nearly all in the context of H. mirabilis which includes ‘magnifica’. This naturally supports my perceptions that H. emelyae is in fact the karoo extension of H. mirabilis. More widely that H. mirabilis, pygmaea, retusa and emelyae form a single system. If one reads in the Updates the reports of Towerlands/Aaasvoelkrans one will appreciate the connection better. The “magnifica’ as a species myth is simply and easily dispelled by studying the floral data presented in updates. There is no reason why there should be any doubt and confusion that the cabal so enjoys and wallows in. Aloe barbara jeppeae indeed.

The truth of the matter is that there is no taxonomic solution other than recognising this and stop prostituting science in the name of populism.  There are hundreds if not thousands of people interested in Haworthia, and millions affected by the formal names of plants. I see some responsibility in respecting this fact and even more so in trying to understand what all this marvelous stuff really means. It comes down to what a species truly is and how it is defined. If I could bring just one person to that realization I might feel comfortable – with no one caring a damn, I am not. :) I have not far or long to go now and I will be posting more on this topic before I am finished.

M.B. Bayer
June 2016

Leaf sequence in Haworthia emelyae ‘comptoniana’ over a long period

Leaf sequence in Haworthia emelyae ‘comptoniana’ over a long period

1 December 2011 16 July 2012 15 September 2012
13 December 2012 13 April 2013 August 2013

Here is an interesting series of pictures showing Haworthia leaf replacement over only 16 months.  The plant is in an outdoor rockery.   Leaves are numbered from oldest to youngest.  Leaf loss has not been quite sequential as the 7th leaf outlived the 5th.  In the growth condition of September 2012 the leaves show three tiers viz. 1,4,7,10,13 / 2,5,8,11 / 3,6,9,12.  The figure for Dec 12 illustrates the “5-tiered” artifact of the spiral sequence with leaves 15/10, 14/9, 13/8, 12/7 and 16/11/6 in each tier.

These pictures demonstrate that the plants grow quite fast.  They may not be very long-lived in nature.  I estimate a life span of 15-20 years?

The first picture of this plant was taken in Dec 2011 when the leaves were numbered 1 to 10. Here in March 2014 leaves 1 through 12 have died away and there are 10 new leaves. At the same time the stem will be stretching as roots are replaced in a similar sequence. The life of the plant is going to be determined by the way in which the old stem and roots decay and how that decay will affect the ultimate health of the whole plant.

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In the field it seems as though the decay of the old leaves and stem is well regulated as a sort of dry composting. In cultivation this can vary from this state to when all the roots and even the base of the stem can rot unhealthily. In the field one does finds moribund old plants that are at the end of their life and with large aged stems. Just how long the plant can maintain good health in either the field or in cultivation is an unknown. A grower just has to depend on experience and feel for his/her plants and this is why some time back I guessed at the normal life of one of these ‘retuse’ haworthia at about 10-15 years. Some things like T. pumila and H. coarctata are quite different as the stems can elongate and re-root along the ground. Plant of H. coarctata more than 3meters in diameter must be very old. Even H. reticulata or H. herbacea do this – look at H. cymbifomis ‘ramosa’. What you can consider is that new leaves and flowers follow a regular process and it is useful to remember that the plants go through a non-growing stage in the year. I tend to think most haworthia grow in the spring and autumn disliking the heat of summer and the cold of winter. But this is just a generalization that points to things that need to be considered. All species are not the same. Good root health is also associated with drainage and adequate air space in the growing medium.

In species like coarctata and reinwardtii – and I doubt that these are two different species – the plants easily lose obvious connection to the mother clone and a single clone can come to occupy a very large area. H. cymbiformis and H. angiustifolia can also spread widely by pieces breaking off to establish somewhere else. H. limifolia does it by stoloniferous expansion as can H. marumiana and H. zantnertiana. But coming back to the solitary non-pupping growth forms it would be interesting to know just where the essential life of the plant resides. Sometimes the stem just seems to get too thick and cutting it back too far also cuts away the support and source of the very young and new centre leaves.

 

Variable chloracantha

Variability – sounds so hackneyed now but still it does not seem as if anybody “gets it”. These are plants from two populations of chloracantha east of Herbertsdale. Two very different soils. One is shale and I show only a single plant from there – the left one of the three unearthed plants. There the plants were “ordinary” chloracantha. But the other locality was exposed “pressure burst” kaolinite such as you get around Riversdale and westwards. Some of the plants reminded me of floribunda and even parksiana. I know of only 6 populations around Herbertsdale and there the plants are different too.

7866 H. chloracantha. E Herbertsdale 100_7472 7827 & 7866 H. ch;oracantha. Herbertsdale 100_7505 7866 H. chloracantha. E Herbertsdale 100_7458 7866 H. chloracantha. E herbertsdale 100_7459 7866 H. chloracantha. E Herbertsdale 100_7460 7866 H. chloracantha. E Herbertsdale 100_7461 7866 H. chloracantha. E Herbertsdale 100_7462 7866 H. chloracantha. E Herbertsdale 100_7463 7866 H. chloracantha. E Herbertsdale 100_7464 7866 H. chloracantha. E Herbertsdale 100_7465 7866 H. chloracantha. E Herbertsdale 100_7466 7866 H. chloracantha. E Herbertsdale 100_7467

A further report on Haworthia mirabilis in the Greyton area.

Appendix 11 to Haworthia Update Vol. 8.

In appendix 6 I reported on H. mirabilis just east of Greyton and also at Schuitsberg further east and south.  I undertook this excursion to fill out on a population at Uitkyk (MBB7092) west of Genadendal illustrated with one image in Haworthia Revisited.  En route we discovered still another population along a road from Caledon to the northwest (8055 Hammanskraal), briefly called at a site east of the bridge on that road crossing the Riviersonderend (MBB8056).  We also visited the population MBB8040 east of Greyton and explored some of the hiking trail between Greyton and McGregor.

The population 7092, H. mirabilis, at Uitkyk, is indeed interesting.  It is a steep riverside, south facing, vertical slope.  There are many plants that may not receive any direct sunshine for most of the summer and of course none in winter.  It is really curious because there are groups of plants that seem to be holding clumps of moss, lichen and a modicum of soil to the rock.  There are orchids, oxalis, shade-loving Asparagus, and all the small bulbs one expects in these moist south facing habitats.  The rock seems to be metamorphosed from fault-shearing heat and pressure on shale.  Among the illustrations is a view looking east along the road with the roadside south-facing habitat on the left.  The Riviersonderend River is immediately on the right.  In the distance ahead is Leeukop, the type locality for H. mirabilis ‘rubrodentata’.  That is a dry north-facing slope.

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The absurdity of taxonomy and nomenclature?

In Alsterworthia 13.1:6 (2013) there is yet another statement about the correct name for a species of Haworthia.  It reads …”The vexing matter of the correct name for Haworthia pumila has taxed some of the finest minds in botanical nomenclature”.  The article then goes on to replace that name with H. margaritifera with an explanation so simple that it casts considerable doubt onto the quality of those minds that have examined the problem.  There is of course also a difficulty in that the quoted sentence implies that H. pumila is the correct name, while the article goes on to dismiss it.

The fact is that Linnaeus listed four different things (varieties) under a single name Aloe pumila, and the only issue was about which of those four things ends up with that particular first name.  It so happened that Burman in 1701 made a choice, and was followed by Aiton in 1789 who chose something else.  So the name Aloe pumila stood but applied to two different things (species).  Duval was unaware of the earlier Burman choice and used Aiton’s choice when he created the genus Haworthia.  Dr L. A Codd, whom I would have accepted as a fine mind (and also as a very ethical man), advised C.L. Scott that Aiton’s choice was in fact illegitimate and hence also Duval’s usage in Haworthia.  The opinion was that Burman’s choice was the first and also thus the legitimate one; and it could not be denied by the illegitimacy of the Aiton usage as a later action.  So perhaps it was/is a question of rank or just an opinion that Aiton made up pumila as an entirely new name.

There is nothing complicated and mind boggling about this simple state of affairs.  Or is that so?   What on earth does the ICN as the product of presumably fine minds actually say about this?  Does it take 50 years of debate to establish such a simple fact?  The situation is further exacerbated in that the finest taxonomic minds are involved in an epic battle to either create a single alooid genus or many lesser genera.  It appears that the latter option is winning ground although the war against single-species genera has surely not been abandoned.  When the dust finally settles, it will be recognised that the taxon onto which this unfortunate species viz.  Haworthia pumila/margaritifera resolves, will be a separate genus, probably Tulista, and then the truly correct name will be Tulista pumila.  Or will it?

My personal opinion that however the case may truly be judged, the correct answer is the intent.  Scott and Codd came to a workable end point way back in history and it has been my misfortune now to have defended that.  I think there is a parallel in the case of Aloe bainesii.  Put into use by Reynolds far back in history, it is found that the name barberae had page priority and thus preference.  In what interest was the change made?  Why does the code have a conservation facility for names?  The fun seems to be in the argument rather than in usage.

The argument that I think L.A. Codd would have made is this.  There are four varieties covered by the Linnaean epithet pumila.  The first effective use of that epithet for one of the four was to the warty t10 of Commelin and that is how the name is formally typified.  To use of that same epithet at any other time for any other of those four Linnaean varieties would be illegitimate.  It is also not in the least certain that the name margaritifera is correctly typified by Wijnands on the same Commelin illustration t10.  I aided Wijnands to this conclusion before myself stumbling on the fact that its correct typification would be on a Bradley illustration.

There is a curious twist to the issue and it is somewhat of an oversight that the persons involved never read the introduction to Haworthia Revisited.   I explained the problem and also in respect to the correct application of the original name margaritifera to what we know as H. minima.  I also cited the name H. pumila with the authors as (L.) Bayer to make it clear that I was not accepting the name with the authors (L.)Duval as Scott cited it.  I thought at the time that it was a mistake on Scott’s part.  I had also written to Dr Codd specifically about the issue and this is when he explained to me (as a professional taxonomist and fine mind) that the illegitimate use of the name pumila in Haworthia did not prevent the correct usage.  It only strikes me now that he probably had advised Scott to the effect that the NAME as Duval had taken it through to Haworthia was correct, even if he had applied it to the wrong species.  This whole issue has not been properly and fully aired.  To argue that it is a new name seems to me just a piece of intellectual vanity that serves no purpose other than to demonstrate our collective failure to honour the intent of the code – or respect the dismay of interested person.  A last point I make is that people can and will always find topics to disagree on, so this is an important trap to avoid and be mindful of.  It is not particularly in the case of nomenclature that this seems to happen.  I had no doubt at the time when I made the decision to accept Scott’s usage that no matter what my decision was, cause would be found to change it.  If I had decided on either margaritifera (correctly typified) or maxima (as I. Breuer later did), this would also have been argued as wrong.

[-ed. There seems to be a number of taxonomic changes brewing.  Time will tell whether pumila survives.]

References:

1. Haworthia margaritifera/pumila
Dr. John Manning. S.ANBI.

The vexing matter of the correct name for Haworthia pumila has taxed some of the finest minds in botanical nomenclature. Since I do not include myself among their company, I was not in the least surprised to find that I had misrepresented the situation. Thanks to expert input from Roy Mottram and Urs Eggli we can now put the matter to rights.

The issue of the correct name for Haworthia pumila starts with the fact that in his original publication of Aloe pumila, which forms the basis for this species, Linnaeus recognized several varieties, but without explicitly listing the typical variety, thus he did not list Aloe pumila L. var. pumila. Linnaeus’ Aloe pumila was subsequently effectively lectotypified by Burman f. (1701) [and later in enor by Scott (1978)] against the illustration in Commelin’s Horti medici Amstelodamensis, which is also the type of var. margarit!fera. This renders the name margaritifera homotypic with Aloe pumila L. (i.e. they share the same type). As the autonym (i.e. following automatically from the species name) for this species, pumila would normally have statutory priority over margarit(fera BUT, in the interim, the combination Haworthia pumila (Aiton) Haw. (1804) had been published, based on the name Aloe arachnoidea var. pumila Aiton, a quite different species that we know now as H herbacea. The publication of this combination renders Haworthia pumila (L.) Duval (1809) an illegitimate later homonym and thus not available for use in Haworthia. Because the combination Haworthia pumila cannot be used for Aloe pumila L. as a result of its prior usage for some other taxon it must be substituted with the next available valid and legitimate epithet, which is margaritifera. Note, however, that in any genus other than Haworthia the epithet pumila is the correct one to be used for this species.

The formal rendering of this situation is as follows:
Haworthia margaritifera (L.) Haw. (1819). Aloe pumila var. margaritifera L. (1753).  Aloe margaritifera (L.) Burm.f (1768).  Aloe pumila L. (1753). H pumila (L.) Duval. (1809), hom. illegit. non H pumila (Ait.) Haw. (1804). Lectotype, effectively designated by Burman f. in Prodromus florae Capensis: 10 (1768) [Superfluous lecotypification by Scott (1985)]: Illustration in Commelin, Horti medici Amstelodamensis, Pars altent: t.l 0 (1701): Aloe Afric: folio in summitate triangulari margaritifera, flore subviridi.

2. International Code of Nomenclature for algae, fungi, and plants (Melbourne Code)

3. Aloe pumila, Haworthia pumila; what or who is confused?  ISBN: 0-9534004-4-1 Bruce Bayer. Alsterworthia International Special Issue No.3. http://haworthiaupdates.org/aloe-pumila-haworthia-pumila-what-or-who-is-confused/
alsterworthia_special_3

 

4. Commelin, Johannes, Horti medici amstelodamensis rariorum tam Orientalis, vol. 2: t. 10 (1701)
http://plantillustrations.org/illustration.php?id_illustration=122192
Commelin t10 1701 H. pumila

 

 

5. Commelin, Johannes, Horti medici amstelodamensis rariorum tam Orientalis, vol. 2: t. 11 (1701)
http://plantillustrations.org/illustration.php?id_illustration=122193&height=750
Commelin t11 1701 H. pumila

 

6. Curtis’s Botanical Magazine, vol. 33: t. 1360 (1811) [S.T. Edwards]
http://plantillustrations.org/illustration.php?id_illustration=8348
ST Edward 1811 Curtis Bot Mag v33 t.13608348

 

7. Moninckx, J., Moninckx atlas, vol. 3: t. 12 (1682-1709)
http://dpc.uba.uva.nl/cgi/i/image/image-idx?c=botanie;view=entry;cc=botanie;entryid=x-421058064 and
http://plantillustrations.org/illustration.php?id_illustration=133655
Moninckx

 

8. History of Succulent Plants,  Bradley, Richard (t30) (1716)
http://www.botanicus.org/page/614136
Bradley t30

 

10. History of Succulent Plants,  Bradley, Richard (t21) (1716)
http://www.botanicus.org/page/614116
Bradley t21

The Haworthia species of the Bontebok National Park

M. B. Bayer (MSc), Kleinbegin Farm, Kuilsriver, South Africa
Mrs Carly Cowell (MSc), Regional Ecologist, Cape Research Centre, Conservation Services, South African National Parks, Cape Town, South Africa.

Objective:  The significance of the Park occurrences.
The occurrence of members of three aloid “genera” (the three sub-genera of the genus Haworthia could indeed be genera) and the absence of any other member of the Aloids (bar the ubiquitous Aloe ferox) must surely be indicative of the driving forces that determine the flora of the Park.  This also must surely help establish the significance of the park as a conservancy of considerable merit.  The complex interaction of the species enhances even that.  The purpose of this report is to examine more closely the variation and nature of a small segment of the Park flora, and demonstrate how much more can be done.     

Note: This report has several constraints.  Firstly is the situation in which there is no formal general definition and hence understanding of what a plant species is.  Secondly there is the generally understood view that there is an evolutionary process at work by which organisms evolve from a common distant origin by genetic mutation and adaptation.  Thirdly there are serious flaws in the classification of the Aloid genera.  Several essays dealing with these issues by DNA sequencing are weak because they rest on those flaws and consequently do not address some serious questions of relationships that the results pose.  Fourthly of course is the reality that the knowledge or intellectual capacity to overcome these deficiencies may be absent.  Thus the report is written in the context of all the publications as the original genus revision (Haworthia Revisited, Bayer; Umdaus, 1999) and others available on the internet (HaworthiaUpdates.org).

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Haworthia flowers – some comments as a character source, Appendix 10

Appendix 10 to Vol. 8 Haworthia UpdateAn additional report on Haworthia mirabilis and Haworthia rossouwii ‘minor’, Rooivlei and Brakkloof, N and, NNE Bredasdorp.

The previous report indicated the necessity for further exploration of Rooivlei.  I had observed H. mirabilis, but not reported it in Update 3, at Brakkloof to the west in 2004.  So the object of this appendix is to remedy this oversight and to also cover more area of Rooivlei.  At Brakkloof there are several small remnants of rocky shale and we located several populations, while at Rooivlei we actually explored the very western boundary.  This constitutes the same topographical area as the Rooivlei populations but the plants we observed were factually on Brakkloof.   

The populations reported on here are:-

  1. 6537 H. mirabilis, Groudini, W Napier
  2. 7285 H. mirabilis, Brakkloof 3
  3. 8046 H. mirabilis, Brakkloof 2
  4. 8047 H. mirabilis, Brakkloof 1
  5. 8048 H. mirabilis, W Rooivlei 1
  6. 8049 H. mirabilis, W Rooivlei 2
  7. 8050 H. mirabilis, W Rooivlei 3
  8. 8051 H. mirabilis, E Rooivlei
  9. 8045+ H. rossouwii ‘minor’, NW type locality
  10. 8052 H. mirabilis, S.Welgegund
  11. 8053 H. mirabilis, Welgegund SE 8052

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Haworthia flowers – some comments as a character source, Appendix 9

Appendix 9 to Vol. 8 Haworthia Update –  A report on Haworthia mirabilis and Haworthia rossouwii ‘minor’, Rooivlei, NNE Bredasdorp.

In Appendix 8, I explain some of the rationale of my use of names.  A detailed report on H. mirabilis can be found in Haworthia Update Vol.3. and in various chapters of the subsequent Updates.  It is shown why I consider the possibility that H. mirabilis and H. retusa are in fact the same species.

In this report I will show just one population of many from Napier northwards and westwards for which no broad name exists.  There is simply a transformation from elements that I refer to as H. mirabilis ‘subtuberculata’ in Appendix 8, to a very wide range of populations in the central Southern Cape.  Both the names “maraisii and “heidelbergensis” have been applied to populations in this area.  The name H. maraisii var. simplicior from Napky may even be relevant but its application, simply irrational.

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Haworthia flowers – some comments as a character source, Appendix 8

Appendix 8 to Vol. 8 Haworthia Update. A report on Haworthia mirabilis ‘badia’ / ‘subtuberculata’

I cannot claim that I have resolved the nomenclature niceties around the use of this name and its many varietal names and synonyms.  If critically examined even the use of the name “mirabilis” is in doubt and the very original epithet of “Aloe atrovirens” may be nomenclaturally correct.  This would create havoc because then the name H. herbacea as typified by W.T. Stearn may best apply.   So I put that all aside and use names as I have in my Revision and subsequent publications.  I am well aware that there is a problem with the use of H. mirabilis var mirabilis where it may be thought that the name “mundula” is therefore redundant.  I cover all this up with the explanation that there is no typical variety “mirabilis”  and actually use just the name H. mirabilis to cover all those populations and variants to which no Latin names exist. I use names like “badia” and “sublineata” as it is generally possible to recognise all or most of the variants from those populations.  But names like “magnifica”, “maraisii”, “heidelbergensis”, “rubrodentata”, “beukmannii” and “depauperata” (among others) have no clear and direct application in respect of a population or even a group of variants of any kind.  In my Revision I attempt the use of the name “triebneriana” to cover all the variants that are not included under the typical varietal name “mirabilis”.  This does not actually work either because the name has its origins at Stormsvlei and there are other populations that are very different from those occurring there too.

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Haworthia flowers – some comments as a character source, Appendix 7

Appendix  7 to Haworthia Update Vol 8.

Three further records and data for Haworthia mirabilis.

The populations covered here are:-

6631 H. mirabilis ‘mundula’, Mierkraal, SW Bredasdorp.
6635 H. mirabilis ‘badia’, NW Napier.
6639 H. mirabilis ‘sublineata’, S Bredasdorp.

There has been some published comment about the distinctiveness of these three populations stating that I do not recognise this because I treat them as variants of single species.  The implication is that I do not see any difference.  This is quite bizarre.  At the present moment I have a digital library of 165 H. mirabilis populations and this is by no means all there are.  There is an enormous amount of variation both in and between these populations.  If the specified three are to be recognised as species, it means that there is a wholly unrealistic number of species quite out of keeping even with an already highly diverse set of species of the Cape Flora.  Furthermore,as I point out in appendix 6, there is no typical variety of H. mirabilis in any practical sense because the variability in the population designated by me, as well as that of Schuitsberg apparently preferred by another, precludes it.

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Haworthia flowers – some comments as a character source, Appendix 6

Appendix  6  to Haworthia Update Vol 8.

Two further records and data for Haworthia mirabilis.

Kobus Venter drew my attention to a second population of H. mirabilis on the eastern boundary of the farm Schuitsberg, which is the origin of the var. beukmannii of von Poellnitz.  But the real motive for exploration in that area was a photograph sent to me by Messrs Daryl and Priscilla Hackland of a plant on the Zigzag Path just east of the northern end of the town of Greyton.   It was their son Andy Hackland who observed the plants and thought I might be interested – indeed.  The bright green colour of the plant struck me as most unusual for that area where most of the populations known are south of the river in shale and they are of the brown and red hues.  This is not strictly true because records of an expedition by messrs Beukman, Otzen and others mentions a small “black” species just before the entrance to Greyton.  I have never found that.

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Just what do we do with names for Haworthia?

Previously published in BCSJl (Cactus World) 30.4:211(2012)
M B Bayer

Taxonomy always provokes differing views, and Haworthia in particular has been subject to years of vacillation.  The author has long been a campaigner against the haphazard proliferation of new names for every new, morphologically different population or variant.  He questions the vagueness of a conventional species concept and pleads for a more reason-based, logical and sensible, communal approach to understanding and classifying Haworthia species.  He hopes in this article to convey a message which is relevant to whatever genera of plants you grow.  Photography by the author.

In Haworthia, professional botanists have struggled with and avoided the group because it is so infused with amateurs whose interest in the genus far outweighs any knowledge of botany.  So classification of Haworthia has muddled on with scant regard for the discipline of botany as a science.  Whether that has changed, is not for me to say.  I have personally been gathering information on distribution and variation for over 50 years and have very seriously tried to keep that in the context of the science I was trained in and present it in a manner that botanists can follow and hopefully accept.

What has developed is that academic and professional botanists have been working with the tools of molecular biology and the results of five independent studies have all pointed towards the same conclusion, which is that the species of Haworthia are elusive, and the related genera are also not adequately distinguishable in the DNA data.  The best solution they can offer is to merge the genera back into a single genus, namely Aloe.  My personal reaction is that this is not a new idea and also Gordon Rowley pointed this out as far back as the 1970’s.  I have also said that the subgenus Haworthia does not sit comfortably with the other two subgenera.  Had I been a true taxonomist I would have implemented that by separating Haworthia into three separate genera and that is what I really would like to see.  But the reality is that this does not solve the other problems that exist regarding Astroloba, Chortolirion, Poellnitzia, Chamaealoe, Leptaloe, Lomatophyllum, and the small Madagascan aloes.  True botany alone can resolve the current and a new classification (still in manuscript form) has been proposed by a group of scientists that will really ‘rock the boat’ as far as collectors are concerned.

In Haworthiad (2012:4), I wrote about Haworthia mirabilis ‘submagnifica’. (Ed. note: The name in inverted commas, according to the author’s system indicates a variant name rather than a formal conventional variety, subspecies or form.  It is his contention that there is no species definition and thus formal names have a large element of uncertainty.  Another option is to drop the use of any rank denotion at all).  It is one of the first populations linked to von Poellnitz’ H. magnifica long before so much was learned about distribution and variation.  I used the prefix “sub” because this means “somewhat”, “almost”, “slightly”, “partially”, and possibly a few other words that mean… it is, but it is not.  The population concerned is Komserante (Figs 1-2) and this particular population has acquired the name H. vernalis (Figs. 3-4).  But I think we need to start from scratch and drop all the ‘baggage’ of the years.  I personally have learned so much since I wrote my revision in 1996 that I know it is not possible to properly backtrack and retrace the passage forward by the use of Latin names.  Interfertility is the basis of the system we use to identify and describe species and my field experience was already proving that this cannot possibly apply in the way in which Haworthia has been, or is to be, classified.

Fig. 4 7778 H. mirabilis 'vernalis'. Komserante 4892 Fig. 3 7778 H. mirabilis 'vernalis'. Komserante 4891

It is quite evident that H. retusa and H. mirabilis, both of which I accept in a very much broader context, do hybridise and there are populations that fit between.  But first let me just explain that I regard H. retusa now to include H. turgida and all the variants of that species (nomenclatural priority obviated the use of the name turgida to cover the greater body of populations for this species).  In the same way I regard H. maraisii, H. magnifica, and H. heidelbergensis and whatever variants were attached to those, as H. mirabilis.  There are thus two species.  My further observation is that H. pygmaea and H. mutica are segregates from the common gene pool of H. retusa and H. mirabilis.  The Komserante population is the one in which that same gene pool is re-combining (Figs. 5-10).  I am not in the least sure of all the intricacies but it seems to me that it is actually the group of populations that I recognize as H. retusa var. nigra that is pivotal in the relationship of all these species that I recognize.  In this we discuss populations using names as prescribed by convention.  This convention caters for chronology and authorship and not for evolutionary pathways.  Both the names “retusa” and “turgida” precede the name “nigra”, but the populations that I now assign to H. retusa ‘nigra’ may better  fit the concept of evolutionary origin.

Fig. 5 7778 H. mirabilis 'vernalis' with a more velcro-like surface. Komserante 4897 Fig. 6 7778 H. mirabilis 'vernalis' resembling plants at Kruisriver. Komserante 4900
Fig. 7 7778 H. mirabilis 'vernalis'. Komserante 4901 Fig. 8 7778 H. mirabilis cf H. retusa, Komserante
Fig. 9 7778 possibly H. mirabilisXH. retusa. Komsernate Fig. 10 7778 possibly H. retusaXH. mirabilis, Komserante

The picture is complicated by the role of H. floribunda.  This also hybridizes with both H. mirabilis and H. retusa as odd hybrids as well as at a population level.  Just what are we to do?  History has demonstrated all too well that a bevy of ill-assorted interested parties trying to impose a botanical classification is going to produce nothing but conflict and confusion.   This has been going on now since the time that Smith, Von Poellnitz and Resende were simultaneously describing new species.  How are we going to turn around and arrive at the understanding and stability of names that we seek?

In the past I have been extremely reluctant to make the following suggestion, and even now am a bit hesitant.  What we need to do is turn to people who are employed to do this work.  Herbaria and herbarium botanists are tasked and entrusted to classify and name plants.  Perhaps it testifies to the complexity of the subject, or just its enormity, that these botanists have too often needed to defer to amateurs who have the interest, energy and enthusiasm and commitment to acquire field knowledge that a professional could never get the time or funds to do.  The unfortunate part is that sometimes amateurs may not be able to relate their knowledge adequately to academic botany.

So what is the solution?  It is that the community leaders assume the responsibility for the establishment of a system of classification that is meaningful to the community they serve.  (By community, I mean initially the botanists who should be providing us with scientifically sound classifications, then editors who are familiar with what botanists do, next are the Societies with their memberships, and also opinion formers in those groups. Finally included are the reviewers and commentators who lead opinion in one direction or another).  It is surely not that difficult to sit down together to discuss and arrive at a set of guidelines by which a decision can be reached as to what (not whose) system to accept.  A solution does not belong to anyone.  Latin names are assumed to refer to an entity called a “species”.  Botany has indeed been very lax and remiss in not providing a definition and this is the prime reason why amateurs have had so much freedom in generating Latin names for the most frivolous reasons.  Botanists themselves have often not been far behind.

I think it is time to change all this and must excuse myself from any decision making body or process because I have a vested interest in respect of all the words I have written on the subject. For further reading please visit http://haworthiaupdates.org

M B Bayer
PO Box 960
Kuilsriver 7579
South Africa

Email: bruce@shadowlands.co.za

 

Literature cited:

Bayer, M B(1999) Haworthia revisited. Umdaus Press, Hatfield.
-(2012) Plants in my collection 7: H. mirabilismagnifica’. Haworthiad 26(1): 4-5

 

 

 

Leaf arrangement in Aloe striatula

Herewith is an image of the leaf arrangement in Aloe striatula. I have numbered the leaves in inverse order to show that the leaves are as much distichious as trifarious i.e in two rows or three. The primary set is 1 through 10, the distichous set is 1, 3, 5, 7, 9 and 2, 4, 6, 8, 10. The trifarious set is 1, 4, 7, 10; 2, 5, 8 and 3, 6, 9. I have also added a picture of the leaf insertion – here it is entire and there is a leaf sheath around the stem – the actual point of insertion is at the pointer although the “veins” continue through that point to the stem itself. In this species the next leaf is inserted just below the opening of the previous sheath. Despite the leaves being alternate, they are spirally arranged. In Aloe broomii the leaf insertion is continuous and you can peel all the leaves off the stem in one piece. In most Haworthias the leaves are imbricate (overlapping alternately) but always in a spiral sequence. H. wittebergensis has leaves that have entire insertion and by memory the same is true for H. blackburniae and maybe for H. viscosa.

 

MBB7989 Haworthia pumila, Lemoenpoort

MBB7989 H. pumila, Lemoenpoort

Kobus drew my attention to a glabrous plant of H. pumila while he was photographing this species at Lemoenpoort. The plants here have a missing chromosome and tend to have a purplish colour. I have seen smooth non-tubercled leaves elsewhere. But do check out that one plant – if you look carefully you can see the leaves are in 8 nearly vertical tiers. Proper botanists recently, for Taxon, described the arrangement of leaves like this in only two tiers (e.g. H. truncata) as “distichous insertion”. This is weird. Are the leaves in this plant of H. pumila “octichous”? Is H. viscosa “tristichous”. No. The leaves in the aloids are alternately and spirally inserted.

7989.1 7989.2 7989.3 7989.4 7989.5 7989.6 7989.7 7989.8 7989.9 7989.10 7989.11 7989.12 7989.13 7989.14 7989.15 7989.16 7989.17 7989.18

 

 

Flower profiles

7989.1a 7989.2a 7989.3a 7989.4a 7989.5a 7989.6a 7989.7a 7989.8a 7989.9a 7989.10a 7989.11a 7989.12a 7989.13a 7989.14a 7989.15a 7989.16a 7989.17a 7989.18a 7989.19a

 

Flower faces

7989.1b 7989.2b 7989.3b 7989.4b 7989.5b 7989.6b 7989.7b 7989.8b 7989.9b 7989.10b 7989.11b 7989.12b 7989.13b 7989.14b 7989.16b 7989.17b 7989.18b 7989.19b 7989.15b

 

Haworthia minima and pumila flowers

6645.1b H. pumila

This flower (H. pumila) is apparently persistently regarded by botanists as actinomorphic (star-shaped, radially symmetrical) – as though zygomorphy (yoke shaped, bilateral, assymetrical) in the aloids is an uncommon condition!

Radial symmetry means the flower can be divided into 3 or more identical sectors which are related to each other by rotation about the centre of the flower. Typically, each sector might contain one tepal or one petal and one sepal and so on. It may or may not be possible to divide the flower into symmetrical halves by the same number of longitudinal planes passing through the axis. Zygomorthic flowers can be divided by only a single plane into two mirror-image halves, much like a yoke or a person’s face.

If you see the way the inner upper petal overlaps BOTH the two lower inner petals, you recognise that there can not be actinomorphy in aloid flowers.

 

 

Haworthia pumila
6645.1a H. pumila 6645.1b H. pumila H. pumila sn. 1a H. pumila sn. 1b H. pumila sn. 2a H. pumila sn. 2b H. pumila sn. 3a H. pumila sn. 3b

 

 

 

Haworthia minima
7519.1a H. min ima 7519.1b H. min ima H. minima sn1 1a H. minima sn1 1b H. minima sn1 2a H. minima sn1 2b H. minima sn2 1.a H. minima sn2 2a H. minima sn2 2b H. minima, Heuningrug 1a H. minima, Heuningrug 1b H. minima, Heuningrug 2a H. minima, Heuningrug 2b H. minima, Heuningrug 3a H. minima, Heuningrug 3b H. minima sn2 1.b

MBB6694 Kanetvlei, Hex River Valley as a variant of Haworthia nortieri.

MBB6694 Kanetvlei,  Hex River Valley as a variant of Haworthia nortieri.

In  Haworthia Update Vol. 9 dealing with H. maculata, I again draw attention to several populations that are problematic in an area very difficult to explore. The populations are MBB7865 at Keurkloof southeast of DeDoorns, EA1441 at the Hex River Pass, an unrecorded population south of Sandhills (about 3km east of Kanetvlei) reported by Ernst van Jaarsveld. In addition there are two populations apparently of H. arachnoidea at Tunnel Station east of Osplaas.

The illustrations that accompany this article are:

  1. MBB6694 Vreesniet, Kanetvlei.
  2. EA1441 Hex River Pass, east DeDoorns.
  3. MBB7865 ex E. Van Jaarsveld, Keurkloof, DeDoorns.

This population MBB6694 is at Kanetvlei southeast of Sandhills, and I originally ascribed it to H. arachnoidea but this is not correctTo this I can add unexamined populations reported by PV Bruynsdeep in the Langeberg at Keerom Damand another of Ted Oliver in the mountains north of Nuy.  MBB6694 is only 200-300m north of MBB7994 also in sandstone.  The sandstone strata are by no means all the same and one can even find shale bands in what is essentially a sandstone formation.  H. maculata flowers late winter to early spring and these other populations in early  summer.

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Bontebok Park Haworthia floribunda and SW Klipport Haworthia mirabilis

I was at Bontebok Park south of Swellendam this week specifically to get another look at Haworthia floribunda there and why it is so different. On the way I did some exploring at Stormsvlei about 25km west of Swellendam where I know H. mutica Klipport in a shale environment, and a very odd H. mirabilis growing on a small patch of manganic conglomerate. But going south onto the northern slopes of the Bromberg we found three populations of H. mirabilis in sandstone that are again “different” in the sense that “H. groenewaldii” could be different from H. mutica. This is just a local geological phenomenon and fully sequential with H. mirabilis to all compass directions. If you extrapolate this to Swellendam you have to conclude that the Swellendam mix of H. floribunda, H. marginata, H. minima, H. floribunda, H. mutica and H. retusa is the way it is because of the unusual geology of the area. The Bontebok Park is a relatively massive area of tertiary gravel of mostly river origin and derived from Table Mountain Sandstone. Tertiary gravels east and south are derived from silcrete and ferricrete. I do not know the detail of the mineralogy but it most definitely forms the basis of the soils, vegetation and habitat across the Southern Cape. I specifically looked at H. marginata in the park and see that it was in seed i.e. September flowering with massive capsules and seed. Now if Marx can persuade someone that this is a different species, I accept that I am a monkey’s uncle and that the differences in H. marginata elsewhere e.g. Drew, Bredasdorp and Heidelberg or Riversdale, mean there are several similar species. OH, I forget – that means H. floribunda would also be several species, and so is H. minima. But then H. mutica is of course several species and H. retusa several dozen. H. mirabilis several hundred.

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Haworthia maculata leaf tips, faces and backs

Die Nekkies – a selection of Haworthia maculata plants with their leaf faces and backs showing variability over this extensive area.

I too the following photographs originally just to show how much the leaves varied in the species. The only locality data recorde was Die Nekkies with no differentiation into populations. The variability was firmly established and became apparent even within populations where the degree of variation surprised even me. It was also extrapolated across the genus.

As an afterthought, this turned my mind to Farden and Smith’s observation about the idiocy of trying to make varieties in Haworthia attenuata on the basis of leaf characters where the individual leaves varied so much that several varieties could be detected from the same plant. This is exactly what Breuer, Marx and Hayashi are actually doing when they get carried away by their justification for new species, drawing conclusions from single plants because of the inability of the mind to hold many images. This is exactly the way in which “H. magnifica” is maintained as a species when the imagery is based on the original single plant originally described. There can be no such thing as “H. magnifica” because the variation across the range of populations from Riversdale to Riviersonderend is so immense and complex.

The following photographs show a random selection of plants and their leaf faces and backs from Die Nekkies. These were taken some time ago when I did not record actual populations. They do record the variability of plants and leaves over this wide area which I classify as Haworthia maculata. For subsequently photographed plants I have recorded my population collection numbers which are indicated on the map found in Die Nekkies Haworthia – A further visit and updated information.

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Die Nekkies Haworthia – A further visit and updated information

Bruce Bayer has now been back to Die Nekkies and returns with more detail to add to the broader Haworthia maculata picture, and considerable detail for H. maculata at its home range located north of the Brandvlei Dam on a low range of hills named Die Nekkies.  (See Haworthia Updates Volume 9, A myth corrected to – Haworthia maculata var. livida (Bayer) Bayer – and flowers ignored). These low hills extend for 10-12km east to west along the north shore of the Dam. They are geologically Witteberg Sandstone and H. maculata is not known off this formation except in the lower Hex River Pass where it is found in Table Mountain Sandstone.  H. herbacea (and H. reticulata) are more abundant on the Dwyka Tillite, and on Bokkeveld and Ecca shales. The Wiiteberg is sandwiched between Bokkeveld Shale and Dwyka Tillite, and Ecca Shale of the Karoo System overlies Dwyka Tillite.  Because of considerable faulting and folding the Cape Terrain is geologically and topographically very broken and there are a multitude of skeletal rocky habitats – the raw rock is very exposed and the surfaces are erosional. Haworthia are rarely found on depositional sites. The fact that there is also a stable and dependable winter rainfall also contributes greatly to the success of small succulents in situations that cannot maintain high biomass levels. This all drives home the fact that Darwin’s dictum that distribution is the lintel to understanding species is doubly true for Haworthia where morphological differences are minimal.

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Haworthia flowers – some comments as a character source, Appendix 5

Appendix 5.

Haworthia mutica, Sandrift, Drew MBB8018 = KG226/70 = JDV92/64

This is an unusual population in that it is the most northwestern one known although only about 15km from Klipport nearer Stormsvlei.  It is the source of the single plant that developed gross milkiness and for which I coined the name “Silver Widow”.   The population was first recorded by a Mr Meiring who worked as a nurseryman for the Bonnievale Nursery of Hurling and Neil in the years at least prior to World War 2.  There is a letter in the Compton Herbarium archive which records a transaction between Meiring and Triebner of 100 plants as 1s ea (i.e. = 10cents in today’s currency.).  I really struggled to find plants again in a very disturbed area  and eventually did so after I had placed “Silver Widow” there in her pot to see if the flowers would be pollinated in situ.  Indeed they were and then found about 20 plants in a very small area nearby.  This visit owes to the report by Jakub Jilemicky of still more plants a very short distance again from these.  Here there are about 80 plants in an area of about so many square meters.

Illustrations of the plants and flowers are given.  The only comment I can make is to repeat that I never ignored the flowers out of ignorance.  The fact is that we have a number of pretentious experts who have no concept of species other than an inherited vague notion that species have something to do with the capacity to interbreed.  The fact that Haworthia plants do so freely does not handicap their enthusiasm for new species either.  So this is a bit of irony.  My contention was that if you did consider flowers there would be a lot less species than even in my conservative approach.  In fact I am quite sure a competent professional taxonomist might well consider that I have been too generous with species and too kind to my critics.

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Comprehension and significance

My writing has been described in all kinds of terms, hermetic and pretentious being two of the adjectives used.  Recently Kris Tamayo also suggested that he had trouble understanding what I wrote or write.  The fact is that writing and expressing yourself is difficult.  But the first place is to be clear about what you want to say.  Or is that in fact the first place?

Writing is a means of communication and it really only should start when you are clear about what you think and what you want to say.  Then it requires that the listener is clear about what he/she wants to hear and has the common cultural heritage that permits communication and understanding to occur?

In writing and talking about plants I personally get very frustrated by the technical problems of definition and knowledge that mess up communication completely.  This is one of the obstacles in classification where there is no species definition and we do not actually know what species are.  There are a lot of other obstacles.  Recently someone wrote and implied that there were a lot of significant differences among Haworthia that could be used to arrive at a better classification (than any already available).  The point I would make is that this person has his own idiosyncratic view of what significance means.   This is not strange at all because a prominent scientist was once applying the statistical measure of standard deviation to two and three measured samples.  That measure probably cannot be used until many more measurements are made.   What is taken to be significant may be quite irrelevant to the actual question of whether there are more or less species.  This is why amateurs and collectors should keep clear of classification.  The professionals already have too many problems.

The characters we use to make identifications are important in that they may be of the yes and no kind i.e. present or absent, or they may be graded from vague to prominent.   So it is very easy to go to one end of the scale and take only the prominent or what happens to strike your eye.  This is exactly what happens.  Unless followers and interested parties realize the impact this sort of decision making affects what they may want to know and understand, there can never be any harmony and peace in the classification process.

Look at these flowers and see what you can glean from them…

 

These just happen to be the only three flowers I have of a few plants of Haworthia herbacea from recent sampling.  They are shown here in correct proportion to one another with the third being 18mm across at widest spread of the two upper outer petals.  So we have two things we can call characters i.e. size and colour that we could say in respect of this simple sample,  that they are significantly different.  No matter how many times or how we measured these two things, this fact would stay the same.  The plants happen to be from two populations and we can then ask if this is true for those populations.  I did ask such a question of both H. herbacea and H. reticulata, and ended up by learning that I needed a sample of about 200 flowers to arrive at a statistically true answer at a probability of 95%.  The thing is that I could go a little further south and sample another population and get a really pink flower with a spread of 25mm or more  that would nearly double the spread of my measurements.

There are several incidentals here.  One is the delineation of the mouth into the tube of the flower.  Why is it so clear in the third picture?  The second is that the first flower has not opened as flat across the face as the other two despite being at the same expected state in respect of time from opening.  The third is that the name “subregularis” was used in this genre of flowers because the petals are so equally spread; perhaps less-so in the middle picture.  Still a fourth curiosity is that in the southwestern species with the more extreme biarcuate bud with the fish-tail tip, is how the tips of the upper outer petals are “replicate” – i.e. the margins tend to fold together.  In the Worcester/Robertson Karoo particularly H. herbacea and H. reticulata have the “regular” flower shape.  But in H. mirabilis in this area, the upper outer petals may be held in a plane directly behind the inner outer petal and do not spread at all.  There the bud tip is still fish-tail and the upper outer petal tips very replicate.

 

 

Haworthia flowers – some comments as a character source, Appendix 4

Appendix 4.

Haworthia flowers – some comments on them as a character source.

No conclusion is written to this appendix.  It is evident to me that there just is no way for me to generate a composite picture for each set of flowers by which one can adequately compare.  In general the summer flowering cf H. retusa set have flowers that are correspondingly lighter coloured than those of the darker flower of the correspondingly darker H. mirabilis set.  While gathering the plant pictures from files it struck me how similar plants are from quite different sets across both groups and persuading me that H. retusa and H. mirabilis are in fact one integral system and H. mutica and H. pygamea are western and eastern offshoots.

Acknowledgement:

I must again appreciate the kindness and helpfulness of landowners in allowing access.  Neels and Suzanne Smit of Volmoed; Hector Odendaal of Dankbaar; Jon and Cindy Webber of Klipport;  Tom,Trevennan and Hesphia Barry of Van Reenens Crest, and Coetzee and Surieta Uys of  Morning Star.  The present owner of the Bromberg site could not be established.  The other plants photographed are not field plants and neither can they be seen as any more than flowers of one or few cultivated specimens with provenance already acknowledged.

 

The following additional populations and plants were observed:-

1. MBB7954 H. mutica, Volmoed.
2. MBB6512 H. mutica, Klipport.
3. MBB7741 H. mutica, Dankbaar.
4. & 5. MBB7920 and MBB7921 H. retusa (nigra), Van Reenens Crest.
6. MBB7803 H. rossouwii, Morning Star, S. Heidelberg.

In addition I include pictures from plants in cultivation:-

7. MBB7758 H. retusa, Skietbaan, S Riversdale.
8. MBB7780 H. retusa (geraldii), Komserante, E Riversdale.
9. MBB7781 H. retusa (foucheii), Komserante, E Riversdale.
10. MBB7776 H. retusa, Pienaarsrivier, W. Riversdale.
11. MBB6747 H. pygmaea, Vleesbaai.
12. MBB3323 H. comptoniana, Georgida.

The population H. rossouwii (elizeae) at Bromberg, Stormsvlei was visited but the plants were only in very early bud.

The Heidelberg H. rossouwii is a small solitary plant and only known to me from two populations.   H. rossouwii (elizeae) is also small, proliferous and very problematic.  It is so far only known to me as one very restricted population. I doubt if the eastern end of the Riviersonderend Mountains have ever been adequately explored to exclude it from there.  Even the Bromberg alone could yield more populations.

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Haworthia mutica (groenewaldii) and its twisted leaves.

In this article Bruce Bayer responds to the notion that apparent leaf twist arrangement is a defining characteristic and further explains his disagreement in recognizing the Buffeljags plants as a new species.  (Also see Haworthia flowers – some comments as a character source, Volume 7, Chapter 4:- What is typical Haworthia mutica?, and Volume 7, Chapter 2:- Further exploration in Haworthia. Further to finale.)  The species definition Bayer uses is that populations are fractal and DNA is governed by mathematical non-linearity.  What does that mean???   We have space with two dimensions latitude and longitude, and we have time with two dimensions – calendar time, and the speed (instability) of the arrangement of the DNA base pairs.  At any moment in linear calendar time there will be an arrangement of the DNA depending on the stability of the DNA.  At one time there will be a clear set of ‘species’ and at another time a different set.  If very unstable there is no grouping at all.   It should be understood that botanists do not use the rank of variety anymore (should not), and subspecies is correct, and that botanical “variety” is not the same thing as a variant.  – Lawrence Loucka

 

Haworthia mutica (groenewaldii) and its twisted leaves.
By M.B. Bayer

There is some argument about the status of this population of plants at Buffeljags.  I have explained my opinion of it based on a species definition that I use.  I also have reported on three other populations a short way away at Rotterdam.  Furthermore I have discussed the flowers at length in a flower report.  These are all available free on Haworthiaupdates.org.  Gerhard Marx does not agree.  The disagreement first has its roots in what constitutes a species and Marx stays with the standard view that characters are what define species.  I opt for the view that species are systems related to geographic distribution and to all the elements that drive vegetation and change (evolution + equals change from some unknown initial condition).  I think these patterns of change and difference are fractal i.e. detailed pattern repeating itself.  Perhaps it would be more correct to say that the organization of pattern is according to a mathematical function which is non-linear.  This means that the end product has many different outcomes.  But this is complexity just of argument that none of us can deal with.

What comes into the geographic nature of species is also the nature of habitat.  What happens is that we have a set of apparent species in Haworthia with a known distribution range.  These species are primarily H. retusa and H. mirabilis.  There is clear evidence that H. pygmaea  and H. mutica emerge from a milieu of populations of those two and that H. floribunda is also involvedBuffeljags is geographically central to this arrangement and the habitat (wrongly described in the description of H. groenewaldii) is very unlike those where the named species generally occur.  It is thus no surprise that the plants appear different.  The Buffeljags population and its habitat also differ to a small degree from the west side of the river, but both are essentially geologically fairly recent river alluvial deposit.

Marx is insistent that the plants at Buffeljags are so different as to be a discrete species and I disagree.  My disagreement is based on my experience of characters in plants.  In Haworthia I think these are few and obscure.  Thus it is almost impossible to delineate or circumscribe a species by characters and no one has succeeded in producing an identification key that can work.  All the differences of opinion and argumentation about names come down to this issue of a species definition and the characters available to recognize them.

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