Pleiospilos nelii, the split rock, splitrock or living granite,[1] is a species of flowering plant in the family Aizoaceae, native to South Africa. It grows in semi-arid areas with rainfall of between 150mm and 300mm, in the Karoo of South Africa.[2]
The species epithet nelii honours the South African botanist Gert Cornelius Nel. The common name "split rock" refers to the appearance of the plant's leaves.[3]
Pleiospilos nelii is a succulent perennial which can reach a height of 5- and a diameter of about 10cm (00inches). This very short-stemmed, nearly stemless plant has one or more pairs of opposite, almost hemispherical, grey-green or brownish leaves. The surface of the leaves has many small dark spots. A new pair of leaves is produced each year, replacing an older pair. This plant closely resembles a small cracked rock (hence the common name), an appearance which may have evolved as a defence against herbivory. The superficially daisy-like flowers are yellow-orange, 6- across, and emerge from the plant's apical bud. The flowers are large in relation to the size of the plant. Each flower opens in the afternoon and closes at sunset, over a bloom period of several days.[4]
P. nelii is one of several plants cultivated for their rocklike appearance. They are sometimes collectively called mesembs.[5] In temperate regions it is grown under glass for protection from excessive rain and hard freezes. It has gained the Royal Horticultural Society's Award of Garden Merit.[6] [7]