2io PORTULACACEAE 



the rays of the sun, diffusing the light before it reaches the green tissue, 

 while at the same time they retard the transpiration of" the leaves considerably. 



They are ot further advantage to the plants in enabling them to 

 absorb rain and dew. All species of Anacampseros^ and specially those of' the 

 section Avonia, inhabit some of the most arid parts of South Africa, where the 

 annual rainfall, on an average, does not amount to four inches, and where yean 

 occur with less than one inch. Hut even in those districts nights with dew are 

 not rare, at least not in winter, and the power to absorb and utilise it must be 

 a ureal help to these dwellers in the desert. 



They also show a striking similarity to their surroundings, and are 

 consequently good examples of protective mimicry among plants. 

 ./. ustu/ata, which occurs on the ordinary grey or yellowish shales of the Karoo, 

 is dull coloured, while A. papyracea and A, albissima, which are pure white, 

 have been found only on fields of white milky quartz, and are consequently 

 detected only with difficulty between the pebbles or in the fissures of the 

 rock. When found all are readily eaten by grazing animals. 



A. UStu/ata is called the moerplantje, as farmers use it for preparing 

 a kind of yeast which is employed in the baking of a favourite kind of pastry, 

 viz. " moer-bolletjes." It is also used in the brewing of beer by the natives. 

 Whether the herb really adds to the efficiency of the veast has not been 

 ascertained as yet. 



In the section Telephiastrum the absorption of dew is effected, although in 

 a less copious way, by the fringe-like stipules. 



Anacampseros Telephiastrum is fairly frequent in all parts of the Karoo, 

 including the Robertson Karoo from Worcester westwards. 



Anacampseros ustu/ata has a wide range, occurring also on the Nieuwveld, 

 while A. quinaria is known only from Little Namaqualand. 



A. papyracea occurs in the Ladismith and Prince Albert districts. 



Fam. 2 2. Portulacaceae. 



(Plate 55, facing page 209.) 



Herbs or shrubs with entire, mostly fleshy leaves. 

 Flowers bisexual (exeept Ccrarni), regular; perianth 

 double; calyx formed of 2 (S. A.) strongly imbricate, 

 deciduous sepals. Corolla formed of 5 (4 — 6) tree or 

 connate, very deciduous petals. Stamens opposite the 

 petals, mostly more numerous. Ovary superior (in Portulaca 

 half-inferior), i-eelled; styles 2—3; ovules 1 oc , on a 

 central basal placenta. Fruit a capsule, mostly valvate, 

 or indehiscent [Portulacaria^ Cerarid) y in the latter 

 eases 1 -seeded, otherwise seeds oc ; embryo peripheric, 

 curving round the farinaceous perisperm, or nearly straight 

 [A?uica)fipscros) . 



