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

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

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

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The ‘Retuse’ Haworthias (1975)

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

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

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Haworthia Revisited – 32. Haworthia retusa

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

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

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

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

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

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

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

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



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




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

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

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

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

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

7778 H. mirabilis. Komserante 4900

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

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Volume 5, Chapter 13:- A February 2009 Miscellany


7807 H.minima.  Swartrug, SE Heidelberg. 002

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

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

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

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

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

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

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

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

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My view of names

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

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New finds in Haworthia.

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

Map - east of Swellendam


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

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

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

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

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Still another view of Haworthia retusa and Haworthia mirabilis

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

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

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

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

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

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

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

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

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

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

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

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

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