ALSO HAWORTHIAS WITH SHORT COMMENTARY ON DESERT PLANTS

Haworthia standeri - a unique species ?

Haworthia standeri was originally described as Haworthia integra var. standeri by J.M. (Essie) Esterhuizen in "Haworthiad Vol. 14 Issue 1 January 2000".

After two failed attempts by me to locate the plants at their type locality at Matjiesvlei NW of Calitzdorp, it was third time lucky for me during October 2009.

The area north of Calitzdorp.


I was most delighted to eventually find a few clones on a steep east facing slope. On previous attempts I had climbed up the wrong slopes, was pressed for time and also rather unsure if I indeed was exploring the correct hill, which incidentally should perhaps rather pass as a mountain, and has a rather peculiar steep westerly bare slope somewhat typical of Haworthia turgida habitats. The bare slope was too steep for me to ascend, but I did some exploration on it higher up it where the going was easier. I could not find any Haworthias there. Only the western and southern inclinations yielded some fruit.


The steep western slope. Gamka River in foreground.


The plants are a most interesting discovery by Mr. Esterhuizen and raise many questions regarding their origin.

Mr. Esterhuizen correctly refers to their rather 'neutral' appearance and the plants being somewhat reminiscent of H cymbiformis, H reddi, H turgida and some others.

Haworthia standeri is very proliferous, a feature less prominent in most Little Karoo species except for Haworthia asema which is found not many kilometers to the east in the Calitzdorp area. A link to the latter species can probably therefore not be ruled out. The general features and habitat of the plants however seem to contradict this relationship.


Haworthia standeri. Very proliferous and growing in shaded pockets.


A smaller clump. All the plants I found were associated with lichens.


Roots exposed. Haworthia standeri makes offsets from the base as well as from stolons from the roots.


The terrain is rather inaccessible and it was difficult to determine their local distribution without the risk of injury, but as far as I could assess the plants grow fairly high up on the mountain and are confined to a steep easterly slope and grow only in deep shaded pockets. This is a characteristic typical of Haworthia zantneriana, but there is no known link to the latter species which indeed is found a few hundred kilometers to the east in the Willowmore- Steytlerville area.

Habitat. The eastern slope is in the left side of the picture. Difficult terrain to climb.


Haworthia standeri has an almost uncanny resemblance to Haworthia reddii and cymbiformis which occur even further to the east with no known obvious links inbetween. Looking for a connection with Haworthia cymbiformis and relatives is tempting since the area north west of Calitzdorp could almost be mistaken for an Eastern Cape landscape. There is a large population of Euphorbia coerulescens which is totally adjunct and far removed from their normal distribution at Jansenville and surrounding areas. Even the (believed to be) Gasteria brachyphylla nearer the R62 has an odd tendency for the leaves to curve downwards reminding one of some Eastern Cape species.

Haworthia reddiiHaworthia reddii from Waterdown Dam. Photograph: Ingo Breuer.


Haworthia standeri from Matjiesvlei. From the collection of and photographed by Ingo Breuer.


Haworthia standeriHaworthia standeri from Varsfontein - IB 3600. This locality I have not been to. Photographed by Ingo Breuer.


A possible link is to Haworthia rodinii (H turgida sensu Bayer) as the latter occurs some 100 km downstream in the Gouritz River area. Certain leaf markings seem to indicate a connection. Plants from the Haworthia turgida group are however more succulent than the Haworthia standeri I have seen. Some illustrations in Mr Esterhuizen's article however show some Haworthia standeri specimens that are of similar succulence as H turgida. I could not find such plants.

The relationship to Haworthia scottii (Gamka East - H arachnoidea sensu Bayer) and Haworthia rycroftiana (H integra sensu Breuer) is a tough one. The rather proliferous nature of H rycroftiana perhaps fits the picture partly but that of H scottii less so. It does appear that the Gamka East form of Haworthia scottii ( and perhaps also H rycroftiana) has some affinity towards Haworthia arachnoidea. A link between Haworthia standeri and Haworthia arachnoidea at Matjiesvlei however seems to be very unlikely.

A mere 5 meters from the first clump of Haworthia standeri I found was a translucent solitary Haworthia arachnoidea/joubertii form, growing semi-exposed in totally different micro-habitat than Haworthia standeri. The H arachnoidea/joubertii form is sparsely distributed more to the southern side of the mountain which is not so steep and the plants have no resemblance to Haworthia standeri. Haworthia viscosa and Bijlia tugwelliae ( a unique large form), also occur on this mountain. Incidentally the H arachnoidea/joubertii becomes more ‘proper’ Haworthia arachnoidea a kilometer or so towards the south.


A Haworthia arachnoidea/joubertii form. Attractive plants, some growing in close association with Haworthia standeri but more exposed.


In my opinion it makes sense to keep Haworthia standeri as a distinct species. Notwithstanding its morphology and possible links to others, it may be better to avoid complexities and the constant shifting of association that so easily leads to a communication nightmare.


Viewpoint from the western slope. Gamka River below and the Swartberg in the background. Much more needs to be explored.

Footnote: Some months after I posted this, I observed that H standeri flowers in February and March. This corresponds with flowering time of  H zantneriana. No other possible relatives mentioned in this post flower during that time.

Reference

Esterhuizen, J.M. A new variety of Haworthia integra from Calitzdorp.Haworthiad. Vol 14 Issue 1-January 2000.
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