Clivia
Distribution and Habitat
Clivia grows in diverse variety of habitats, from coastal forest and secondary coastal dunes, to swamps, riverbanks rocky screes and cliffs, and even as epiphytes on trees. Preferring cool, shaded, well drained habitats when located in summer rainfall areas, the exception is C. mirabilis, which has a localised distribution in a semi-arid area, with Mediterranean climate and winter rainfall. Clivias normally occur in rather inaccessible, isolated locations and the populations are usually extremely old, with some populations producing very little seed and surviving due to their ability to regenerate vegetatively.
Clivia is endemic to South Africa and Swaziland, although unconfirmed reports have placed it in Mocambique and as far north as Kenya and Uganda. The distribution is along the coastal and inland Afromontane forests of southern Africa, extending in an eastwards direction, from the coastal areas of the Eastern Cape Province in the south, through KwaZulu-Natal Province, Swaziland and Mpumalanga Province to the Soutpansberg in Limpopo Province, with C. mirabilis growing among relictual evergreen Afromontane forest elements in the southwestern corner of the Northern Cape Province.
The Afromontane Archipelago-like Region of Endemism can be traced as a series of isolated floristic areas distributed from the southwestern corner of the Northern Cape Province, southwards to the Cape Peninsula and then northwards along the southern and East African uplands, to northeastern Africa. The region generally has a temperate climate with high rainfall, anything from 700 mm to 2000 mm annually. In southern Africa, this region is centred in the Lesotho and KwaZulu-Natal Drakensberg and Midlands, extending north- and southwards along the Great Escarpment. A second centre, containing the largest contiguous block of forest in the subcontinent, is located on the coastal platform of the southern parts of the Western and Eastern Cape. Dominant canopy species in Afromontane forests are 30-40 m high, with those in the Albany Centre 2-10 m in height.
Biogeographically, Clivia evolved and moved as part of the family Amaryllidaceae which originated in western Gondwana and today has three centres of diversity, in the Andean region (28 genera), Mediterranean (8 genera) and southern Africa (18 genera). The greatest diversity of the African Amaryllidaceae is concentrated in South Africa. Clivia , as part of the sub‑Saharan tribe Haemantheae, has all species situated in South Africa (though two occur also in Swaziland) and most probably originated in south‑southwestern Africa. Increasing aridity, the uplift of the continental mass and fluctuations in Africa’s climate resulted in the Amaryllidaceae diversifying and adapting to increasing drought. Clivia adapted by developing thick, fleshy, perennial roots, adapted to growing in the top humus layer of the forest floor.