Seldom seen in cultivation in southern Africa, the highly ornamental, lantern-like flowers of Sandersonia aurantiaca are universally admired, and highly prized as long-lasting cut flowers and graceful container plants.
Sandersonia aurantiaca is an erect or suberect, deciduous, summer-growing geophyte reaching up to 1 m high, and the genus contains just one species. The subterranean storage organ or rootstock is a fairly deep-seated, stoloniferous corm consisting of two swollen, jointed lobes. New growth is produced in spring; the new rootstock and slender aerial stems are produced from a bud at the tip of one of the two old, swollen lobes. The lance-shaped leaves are arranged alternately along the stem, and unlike the closely related genera Gloriosa and Littonia, do not usually have tendrils at their tips. The elegant, lantern-like flowers of S. aurantiaca are borne on long stalks produced in the leaf axils; they open from the bottom upwards and occur in shades of pale to deep orange. The fruit is a capsule containing many small, hard brown seeds, without a papery seed coat.
Distribution and habitat
Sandersonia aurantiaca flowers were once a common sight throughout its grassland and forest margin distribution range in the Eastern Cape, KwaZulu-Natal, Swaziland and southern Mpumalanga, but severe habitat loss from agricultural expansion and indiscriminate picking of flowers has made it a rare sight in the wild today; it is usually only seen in nature reserves. It occurs in deep, heavy soil on damp hill slopes in full sun.
Uses and cultural aspects
The rootstocks of Sandersonia aurantiaca have traditionally been used by the Zulu people
as an aphrodisiac, and the leaves are also used in combination with other plants in bathing infusions as protection against evil. The compound colchicine is present in this species, and all parts of the plant should therefore be regarded as potentially toxic.
Growing Sandersonia aurantiaca
They can be successfully grown in deep bulb beds, provided that the dormant rootstocks are kept dry during the winter months. The flowering time of S. aurantiaca in the wild is mid-December to January, but under cultivation in southern Africa it tends to start earlier, from late November onwards.
New Zealand bulb growers have successfully commercialized this plant, and in the mid 1990s it was that country’s second-most important export cut flower crop after orchids.
Sandersonia is not especially susceptible to pests, however aphids may attack new foliage in early summer, while snout beetles sometimes damage the flower stems. Slugs and snails are partial to the foliage. Fungal rotting of the rootstock is the most important disease affecting these plants and it can be greatly reduced by growing them in a well-aerated, well-drained, sandy medium, and by ensuring that the rootstocks are kept in dry soil throughout the winter dormant period.