These peculiar little plants occur in the northwest corner of the Richtersveld (Oranjemund to Koekenaap), where they form rather dense mats.
They have tuberous roots and tough and fibrous aerial stems, which are more or less terete, 30-100 mm long and 2-5 mm in diameter. The stems do not stick out more than a few cm above ground, as a result of the continuously blowing sand-blasting winds; they are protected by a thick leathery skin.
The flowers appear from April through September and are usually yellow-green (Williamson in his Richtersveld book gives the colour as mainly chocolate to orange-brown).
Subspecies namaquensis differs from its sibling by having no more than two leaves, one of which is usually inconspicuous.
The inflorescence is shorter (5-10 cm tall) and always single and the filaments have a double tuft of hairs.
These plants occur only in the Northern Cape, from Springbok to the Richtersveld in gravelly places.
Almost two years ago I published a post on Othonna auriculifolia. Today’s subject could be considered the northern counterpart of that species. Both were described in the first half of the 19th century, when taxonomy was still a very European science. This probably explains why both specific epithets refer to well known European plants: taraxacoides means looking like a Taraxacum (dandelion) and auriculifolia means with leaves like Primula auricula (bear’s ears or cow slip).
O. taraxacoides is a stemless tuberous geophyte up to 10 cm tall. The leaves are leathery and wedge- to egg-shaped or more or less kidney-shaped. Usually they are 2-3 cm long and up to 2 cm wide, with small rounded teeth and often incised with 3-5 rounded lobes.
The flower heads are 0.8-1.5 cm in diameter and appear in July and August.
The plants occur on open pebbly places or quartz patches from the
Richtersveld to Kamieskroon.
Of the small-flowered Hoodias this is by far the tallest, with plants growing into many-stemmed shrubs up to slightly over a meter tall and 0.5 m wide.
The stems have an unusual whitish, grey-green colour and their 20-22 obtuse angles are armed with exceptionally hard and sharp spines.
The upper parts of the stems produce large numbers of flowers 1-1.8 cm in diameter.
The species has an unusual distribution. It occurs in the winter rainfall area of
Namibia on stony hillsides east of Luederitz and along the lower reaches of the Orange River.
In South Africa it also occurs along the lower Orange River: the western part of the area here receives rainfall in winter, whereas in the eastern part the rain falls in summer.
These habitats are surprisingly arid and in general the plants grow in the open on either rocky slopes or stony, flat areas.
These pictures show subspecies namaensis.
Even if one has no knowledge of Latin, it is probably easy to understand that papyracea means papery. This refers to the thin, white scales that cover the stems.
These scales are in fact modified stipules: outgrowths of the base of the leaf stalk. By reflecting and diffusing light, they act as sunshades. This effect, combined with controlled aeration*, reduces evaporation. The scales are also able to trap dew.
*It has been noted that in hot, dry conditions the scales tightly overlap each other like roof tiles, whereas in cooler and therefore damper weather they can open out to some extent so that the leaves are more exposed.
As Gordon Rowley in “Anacampseros, Avonia, Grahamia” (1995) remarks, it seems surprising that such an efficient adaptation has, apparently, evolved only once.
The scales are about 5 mm long and wide and hide the minute leaves.
The stems are usually about 5-8 cm long and 0.7-1 cm thick, arising from a thickened tuber. As in other Avonia species, the stems that carry flower buds grow more or less horizontal, but become erect on the day of flowering and stay that way until the seeds have been dispersed.
The scented flowers are creamy white and appear in late spring and early summer.
There are two subspecies: subsp. papyracea occurs throughout the Little Karoo and is also found in the Great Karoo, whereas subsp. namaensis occurs in southern Namibia, the Richtersveld and Bushmanland. Both subspecies seem to feel most at home amongst white quartz pebbles.
According to the literature the main difference between the two is that in the first one, the edges of the scales are entire (without any teeth or other incisions) and in the second one saw-edged to toothed.
The following pictures show plants of subsp. papyracea.
These peculiar plants produce leaves of two kinds: the first pairs of the season are egg shaped, forming a bilobed body; the second ones are much longer than wide, with the leaves free for about two thirds of their length.
The plants are cushion-shaped and up to about 30 cm in diameter. They are found from the Richtersveld to southern Namaqualand, in loamy soil, often with quartz pebbles.
The flowers appear in winter and are either dark pink throughout, or rose with a white base, or white (turning pink with age).
The first two pictures were taken 6 Sept. 2010 (look at the Crassula elegans and Conophytum saxetanum keeping the first plant company)
The flowering plants were photographed 11 July 2011