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|Distribution:||Africa: South Africa: Western Cape:|
The following article by Gerhard Marx gives an in depth discussion about Haworthia jakubii and is also a direct reply to a previous article by M.B. Bayer. Marx's article highlights how important it is to study plants in cultivation before any quick and often erroneous deductions are made by simple field observations. It appears that Haworthia jakubii could well be one of the links between the Haworthia mirabilis/magnifica/maraisii group and Haworthia retusa related plants making perhaps all the coastal retuse plants (and some others) genetically not very distant. A workable species concept in the genus that is both consistent and user friendly still remains a challenge. The authors that use more names are less likely to confuse our filing systems in the future as long as uncertain species groupings are left outside the taxonomical hierarchy.
Haworthia jakubii I. Breuer. - Article by Gerhard Marx.
During early March 2008 I joined Bruce and Daphne Bayer and Kobus Venter to explore the area north-west of Still Bay with the main purpose to look for H. jakubii. Details of the habitat had been kindly provided by Jakub Jilemicky after whom the plant was named.
Finding the H. jakubii habitat was quite easy as the population is on a road reserve and not far from the where the road crosses the Kafferkuilsrivier. Upon seeing the plants in the wild, Bruce explained that these are identical to plants that he had seen ca 5 km to the north on the farm Windsor and he then later proceeded to take us to Windsor farm to see the latter plants as well.
Soon afterwards Bruce Bayer published an account of these habitat visits in chapter 14 of Haworthia Update Volume 5, part 2, titled “ Haworthia jakubii – another new species? “. The article features several habitat photographs of ‘MBB 7818, Windsor’ and ‘MBB 7820 Klipfontein’. The latter locality ‘Klipfontein’ refers of course to the H. jakubii type locality which was given by Ingo Breuer as ‘Melkhoutkraal’. On a map the locality looks indeed to be closer to the farm Melkhoutkraal than to Klipfontein, but strictly speaking the spot falls within the Klipfontein farm boundaries. Or, perhaps it should be added ‘just outside the Klipfontein fence’, since it is on the road reserve (Pic 1).
In above-mentioned Update 5 article, Bayer goes ahead and answers the question in the title in a characteristically contemptuous discussion, concluding that the plants should just be referred to as “H. mirabilis ‘jakubii’” and that although it is a “significant population” it is not worthy of recognition within the nomenclatural system of formal botany. This may all seem quite convincing to the general reader and at first glance the habitat pictures published with the article seem to support the arguments. In fact this article is the perfect example of how easily one can be misled by such commanding arguments based upon and supported by a few brief snapshots of the appearance of Haworthia plants in habitat.
In previous articles I have pointed out repeatedly that one cannot learn a great deal about the true identity of Haworthias by only doing brief field observations. It is a necessary part of the natural and inherent protective measures of these plants to present themselves with a certain amount of humble disguise and indistinctness in the wild. Hence the confusing similarity with which geographically adjacent different elements often imitate each other in the wild. The case of these Windsor and Klipfontein plants is a good example.
The photographs below were taken by myself on 8 March 2008, featuring plants in the wild and are therefore very similar to the ones in the Haworthia Update article. Both the Klipfontein and Windsor plants seem to display a somewhat similar dull grey-red and grey-green range of colours and no drastic differences are apparent.The Windsor plants in habitat (Pic 2) during mid-summer and the Klipfontein plants (Pic 3) (H. jakubii) photographed on the same day.
The photo below shows plants from these two localities after being grown for three years under similar light and watering conditions next to each other in cultivation…. A totally different picture indeed!In fact, it is hardly necessary to add much of a discussion as the photo tells it all. Any sensible observer will admit that these are two considerably different plants.
Upon closer observation and looking at the leaf morphology alone, the following differences can be listed between the Windsor plants and the Klipfontein plants (H. jakubii):
Leaf margins smooth or lined with numerous Leaf margins have fewer and larger teeth. very small teeth.
Leaves wider and dull grey-brown in colour. Leaves narrower and bright green in colour.
Leaves acuminate with flat to subtly convex Leaves strongly acuminate with long end-awn, upper areas. and distinctly convex above.
Leaves per rosette up to 18 in number. Leaves per rosette up to 26 in number.
With above facts in mind and looking back at the habitat pictures of both, one can start seeing the differences even in the habitat plants to some extent, but the situations in the wild involve numerous disguising factors. In this particular case these pictures were taken during early March which is the dry and dormant season for these plants. This means that even a bright green plant like H. jakubii will generally be grey-brown and suntanned and somewhat shrivelled in the wild at this time of the year. A second important and ‘unnatural’ factor in this case is that the H. jakubii locality at Klipfontein is less than a metre from the side of a dusty gravel road and these plants are covered with dust most of the time, but particularly so during the dry summer. The Windsor plants are growing far from a road on a remote upper slope of a west-facing river bank and although dry and shrivelled, there is not the dust factor.
In my view, these Windsor plants compare very well with the H. magnifica populations ca 20 km to the north in the Platkop and Soetmelksrivier areas (Pic 6 & 7), as well as with the well-known ‘asperula’ form at Komserante near Riversdale.
As can be seen from obvious features on the photographs, the Windsor plants do not differ significantly enough from the latter to justify a separate formal reference. In the case of H. jakubii from Klipfontein/ Melkhoutkraal area, the determination of the closest ally is less easy. Both Breuer and Bayer linked it to the paradoxa variety occurring 25 km to the west at Vermaaklikheid. Breuer lists it as H. jakubii within Aggregate Paradoxa while Bayer views it along with H. bobii from Infanta as synonymous with ‘H. mirabilis var paradoxa’ (Pic 8) .
The comparisons with paradoxa seems to be mainly influenced by the geographical proximity of the two because morphologically the differences between jakubii and paradoxa are certainly unconcealed enough that it is easy to distinguish between them at a glance. In fact, the comparison of the two also brings up the necessity to define and evaluate the differences between H. magnifica and H. mirabilis. The roughly tubercled leaf-sides of paradoxa links it convincingly to H. mirabilis while the silvery-white flecks in the leaves of H. jakubii suggest connections to H. magnifica and H. pygmaea.
However, perhaps no further verbal elaboration is needed at this point as the main purpose of this article is just to emphasize the existence of an attractive and most interesting and rather distinct Haworthia variety that has not been given deserved attention to date. To what species it needs to be linked is a question that can only be answered after the currently continuing cluttered concept of H. mirabilis has been fully clarified.
Haworthia mirabilis as presently applied seems to be flawed at its very basis and needs redefinition, but that is another lengthy discussion.
References: Bayer, M.B. 2009. Hawortia Update. Essays on Haworthia. Volume 5 Part 2, Chapter 14 : 167-169.
Bayer, M.B..( 2012) . A rationalization of names in Haworthia. A list of species with new combinations and new synonyms. ( Alsterworthia International 12 (1): 7 -17.
Breuer, I. 2010. The Genus Haworthia. Book1 . Alsterworthia International.
|H. jakubii.||H. magnifica at Windsor.||A Windsor plant seen close-up. Note the very small and more numerous suppressed teeth along the margins.||Close-up view of the leaves of H. jakubii. Note the sparse but larger teeth on the leaf margins white flecks inside the leaf windows and opaque leaf sides.|
|Pic 8. H. mirabilis var paradoxa in habitat SE of Vermaaklikheid.||Pic 6. H. magnifica ( ='subsplendens'sensu Bayer) in habitat NE of Platkop east of Riversdale.||Haworthia jakubii in flower during late January.||Pic 5. The Windsor farm habitat of Haworthia magnifica on the eastern bank of the Kafferkuils river.|
|Pic 3. Haworthia affinity magnifica at Windsor. Pictures 2 and 3 taken on the same day during midsummer.||H. jakubii.||Pic 7. H magnifica NE of Platkop.||H. magnifica at Windsor.|
|Pic 3. Haworthia jakubii in habitat at Klipfontein.||Pic 4. After three years in cultivation under identical conditions: the Windsor plants are seen on the left and the H. jakubii plants from Klipfontein on the right.||Pic 1. The roadside habitat at Klipfontein (H. jakubii).|
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