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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A myth corrected – part 5

Set 10.  Map point 18.  H. herbacea ‘submaculata’.  Brickfield, Brandvlei Dam.
Figs. 10.1 to 10.20 MBB7995 H. herbacea, S Brandvlei Brickfield.
Figs. 10.21 to 10.53 MBB7996 H. herbacea, E Brandvlei Brickfield.

I have associated this locality with vonPoellnitz H. submaculata and treated it as a synonym of H. herbacea.  However, here I first illustrate a population about 600m south of that where the plants are in the usual size range for the species ie.30-40mm diam.  At the locality east of the Brickfield and next to the Breede River, the plants are 1/3 to 1/2 as large again and can form huge clumps.  North-west from this is a population of H. maculata at the extreme end of Die Nekkies and only about 300m distant, and this population I have always regarded as somewhat intermediate.  What is interesting to note is the huge variation in leaf shape and armature within each population.  In both cases the plants are in Witteberg Sandstones and at the first site this is both in a very shale-like stratum as well as in a highly quartzitic one.  This is unusual for H. herbacea.  Both populations wedge in geographically between H. maculata populations and in no known case do both occur.

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A myth corrected – part 3

Set 5.  Map points 6, 9, 13, and 14.  Ouhoekberg.
Figs. 5.1 to 5.24 MBB7991a H. maculata, Ouhoekberg E.
Figs. 5.25 to 5.28 Panoramic views.
Figs. 5.29 to 5.33 MBB7991b H. maculata, Ouhoekberg.

These populations were first observed as one on a higher eastern point of the Ouhoekberg above Moddergat in about 1975.  George Lombard accompanied Kobus Venter and me there in 1996 and we found them on the western high point.  I located them nearby in 2004.  We found them again recently as two more populations on the eastern heights near where I must have observed them first.  Note the reticulation in the dried fruit capsule.  It can be very much more evident in species like H. pulchella but I seriously doubt its diagnostic value.  I have included views to… (a)  north to show the water of the Brandvlei Dam in the far distance.  The area between has not been adequately explored.  What is interesting is the geology.  The mountains on the left are the Table Mountain Sandstones, nearer is the valley where the soft Bokkeveld Shale has been eroded away, and then comes the Witteberg Sandstone with a neck of soft shale, and then low down is Dwyka tillite.  H. herbacea is present on the Dwyka outcrop barely visible in the middle right.  (b) The second view is looking east at first the Hammansberg and beyond that Ouhangsberg with H. mirabilis on its eastern flanks.  The view looking southeast is over low Bokkeveld shale ridges with an abundance of H. herbacea.  The view south is to Villiersdorp where Wolfkloof (not the Robertson Wolfkloof) is a deep valley behind the Table Mountain Sandstone left of the gap through the Rooihoogte Pass.  Here is where H. herbacea ‘lupula’ occurs, unusually in sandstone.  Altitude and skeletal soils of different origins contribute hugely to the genetic mosaic.  Arable depositional soils exclude Haworthia and obviously inhibit contact between populations.

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A myth corrected – part 2

Set 3.  Map point 5.
Figs. 3.1 to 3.34 MBB7066 H. maculata, Lemoenpoort.

This is the type locality (ie. MBB1128, W. Lemoenpoort) for H. maculata var. livida that I think is largely untenable or unnecessary fragmentation.  Lemoenpoort is the valley that separates Hammansberg from Ouhangsberg.  The first few plants seen were in exposed situations and had the purplish or bluish-grey colour that prompted the latin name.  This was maintained in cultivation.  I linked it at the time to H. pubescens that seemed more probable at the time than to H. maculata and then simply because of the perceived demands of a relatively inflexible nomenclatural system.  There are now seven new populations that contribute and improve understanding of H. maculata as a species.  All these localities are in Witteberg Sandstone and the type locality is only slightly different in that the stratum of rock is less feldspathic (i.e. mineralized).

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A myth corrected to – Haworthia maculata var. livida (Bayer) Bayer – and flowers ignored.

(Haworthia maculata var. livida (Bayer) Bayer, comb.nov.  H. pubescens var. livida Bayer in Haworthia Revisited, p.134, 1999, Umdaus)  Type: Cape-3319 (Worcester): S Lemoenpoort (-CD), Bayer 1128 (NBG, Holo.).

I described Haworthia pubescens var. livida in Haworthia Revisited (Umdaus, 1999), in the full knowledge that it was in a twilight zone of inadequate information.  It is a good example of how Latin names give plants a false reality.  The system forces decision making without any slack being cut for doubt.  This is thus a good opportunity to demonstrate what inexperience and ignorance add to the process of classification.  In the small area along the Breede River north of the Brandvlei Dam near Worcester, the species H. herbacea, H. maculata and H. pubescens grow in close proximity.  H. herbacea is ubiquitous throughout the Worcester/Robertson Karoo, while H. maculata has a curious distribution in that area.  It occurs at widely separated localities on the western fringe of H. herbacea and I have wondered about its relationship to that species because of the similar flowers and flowering time.  H. pubescens is only known from a small set of low ridges east of the Brandvlei Dam where it grows in close proximity to H. herbacea.  It also has similar flowers but it flowers a little later in late spring as opposed to early spring.

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