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 reddii from Waterdown Dam. Photograph: Ingo Breuer.


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


Haworthia 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.

Haworthia marxii. South east of Laingsburg

Haworthia marxii is probably one of the most interesting recent discoveries of Haworthia.

The plants were documented by J.D. Venter several years ago, as Haworthia bayeri "Rooinek Pass". The latter refers to a mountain pass south-east of Laingsburg. This given locality for Haworthia bayeri has always seemed questionable as:

1. Rooinek Pass is north of the Swartberg in the western Great Karoo, a vast arid expanse where no retuse Haworthia has ever been recorded.

2. The most westerly known distribution of Haworthia bayeri is in the Oudtshoorn district, which lies south of the Swartberg in the Little Karoo. This leaves a gap of some 140 km between the Rooinek Pass Haworthia and the nearest known Haworthia bayeri and more than 70 km from any other retuse Haworthia ( which is a form of Haworthia maraisii from near Barrydale).


Gerhard Marx and Martin Scott were the first to re-explore the area and when the plants were eventually found it quickly became clear that the plant J.D. Venter referred to is actually a new species, the only retuse Haworthia known from the western Great Karoo, and many kilometers removed from any other retuse Haworthia !

The rather attractive plants were then described by Sean Gildenhuys as Haworthia marxii ( ALOE 44:1: 2007, p. 4 -8).

At first glance, especially during times of drought, Haworthia marxii does have some resemblance to Haworthia bayeri.

In habitat both species have the "muddy" appearance of the leaf epidermis. This is where the similarity ends however. The following differences between the two species are noteworthy:

While H bayeri normally contracts with its leaves deep into the soil, Haworthia marxii is a shallow growing plant. H bayeri has thick fleshy roots similar to H truncata, whereas Haworthia marxii has thin roots. Haworthia marxii has white little dots in the leaf windows similar to Haworthia picta. This feature is absent in Haworthia bayeri. The leaves of Haworthia marxii are also flatter with the tips ending in a sharper point.

Furthermore, the flowering peduncles of Haworthia marxii are very thin compared to the thicker ones of Haworthia bayeri. The flowering period, February, is also considerably later than that of Haworthia bayeri and one rather unusual aspect of Haworthia marxii is that the plants grow in rock crevices on steep sandstone mountain slopes at an altitude of about 1000 meters. Haworthia bayeri occurs on lower hillsides amongst ferricrete pebbles.

There is little doubt that Haworthia marxii is a good species. It is also a very important discovery as it now opens the door for possible other retuse Haworthias to be discovered in the Great Karoo !

Haworthia marxii proved to be difficult in cultivation and is very slow growing from seed.


Haworthia marxii in habitat growing amongst sandstone. The plants do not withdraw into the soil.


Haworthia marxii, a slight resemblance to Haworthia bayeri.


Haworthia marxii amongst lichens at high altitude.


Haworthia marxii. Lanceolate leaf showing white dots.


Haworthia marxii flower on thin peduncle.

Notice: 19 February 2012: A recent revision by Bruce M Bayer, regarding Haworthia marxii as synonymous with Haworthia emelyae (picta) is very surprising as the plants do not occur in the geographic area of Haworthia emelyae (sensu Bayer) and are obviously very different. This raises questions about objectivity and proper analysis.

Notice: 11 July 2012: Recently  Mr. Bayer has accepted Haworthia marxii as a good species. The reasons for its initial inclusion under Haworthia emelyae (picta) will not be mentioned here.