FRITHIA

This miniature leaf succulent is attractive even when not flowering as the windowed leaves with crenulate markings are showy and unique.
Description
This minute plant comprises a cluster of succulent, spirally arranged leaves, windowed at the tips. The windows are just visible above the soil surface and thickened rootstocks are formed underground.

The stems are much reduced and during periods of drought the plants retract into the sandy soil. This has been thought to be achieved by means of contractile roots, but no such roots have been found. The cells of the leaves are arranged in columnar rows and when moisture is lost and the contents shrink, the tangential walls contract, drawing the plants deeper into the soil. This this way they avoid desiccation during the dry winter months and times of drought. Retraction into the ground is thus achieved by means of contractile leaves, not contractile roots.
Flowers are white with a yellow centre, sometimes tipped with light pink. They are generally about 15-20 mm in diameter and are borne singly on very short stalks or are stalkless. They are subtended by five unequal sepals closely resembling the cylindrical leaves. The petals number between 20 and 30 and usually have acuminate tips. After pollination flowers turn pink or yellow.
Fruits are very delicate, spongy capsules resembling a barrel and open when wetted and close again when they dry out (hygrochastic capsules). However, the capsules become detached from the plants and break up shortly after ripening, releasing the seeds. This is an unusual feature as most other capsules in the family are woody and open and close repeatedly as they become wet (open) and dry (closed).

Distribution
Frithia humilis is one of a few mesembs growing exclusively in the summer-rainfall region of South Africa. It is restricted to two provinces of South Africa, namely Gauteng and Mpumalanga. 

This plant is Red Listed as Endangered ( IUCN Species Survival Commission 1994) as only nine subpopulations are known (Burgoyne et al. 2000). One subpopulation was lost because of pressures on the habitat. All the populations together cover less than 2 hectares. The populations are severely fragmented but many seed capsules are produced every year and plants seem healthy.
http://www.plantzafrica.com/plantefg/frithhum.htm


Frithia Pulchra





Frithia humilis