Ansellia is a monotypic genus of orchids in the family Orchidaceae (order Asparagales), containing a single species, Ansellia africana, commonly called the leopard orchid or African ansellia. Some authorities treat it as a species complex of closely related forms sharing a common floral structure and growth habit, though it is widely accepted as a single variable species.
The plants are large, perennial epiphytes — occasionally terrestrial — native to tropical and subtropical Africa, where they grow attached to the branches of tall trees along coasts and rivers, typically below 700 m elevation. Ansellia is notable for producing a distinctive "trash basket" of upward-pointing white needle-like aerial roots that encircle the tall, many-noded, fusiform pseudobulbs and catch falling leaf litter and debris, from which the plant draws nutrients through mycorrhizal fungal partners. This habit is shared with the genus Grammatophyllum, and both are informally called "trash basket" orchids. The pseudobulbs can reach 60 cm in length, and mature clumps can attain an estimated weight of over a tonne — large enough to host nesting eagle owls.
Each pseudobulb bears 6–7 narrowly lanceolate, pleated leathery leaves and gives rise to a branched paniculate inflorescence up to 85 cm long, carrying 10 to 100 delicately scented flowers about 6 cm across. The tepals are yellow or greenish yellow, lightly to heavily spotted with brown, giving rise to the common name "leopard orchid." The three-lobed lip ends in three yellow projections. Individual flowers are short-lived — seldom lasting more than 10 days — but are produced in great abundance. The plant uses CAM photosynthesis, and leaves take on a yellowish coloration under adequate light levels.
The genus was named in honour of John Ansell, an English assistant botanist who collected the first specimens in 1841 on Fernando Po Island (now Bioko) in West Africa.
Etymology
The genus name Ansellia honours John Ansell, an English assistant botanist who collected the first specimens in 1841 on Fernando Po Island (now Bioko), off the coast of West Africa. In the horticultural trade the genus is sometimes abbreviated as Ansel. or Aslla.
Distribution
Ansellia is native throughout tropical and subtropical Africa, growing epiphytically in the canopy of tall trees alongside coasts and rivers. It is most commonly found at elevations below 700 m, though it has been recorded up to 2,200 m in some parts of its range.
Ecology
In its natural habitat Ansellia grows as an epiphyte in the canopy of tall trees, where it constructs a basket of upward-pointing aerial roots to trap falling leaf litter and organic detritus. Nutrient absorption from this accumulated debris is carried out by mycorrhizal fungal symbionts rather than by the aerial roots directly, which are non-absorbing. The plant uses CAM photosynthesis and is highly drought tolerant, capable of surviving months without rain; flowering typically occurs at the end of dry spells.
Cultivation
Ansellia africana is considered relatively easy to cultivate but demands very bright light — approximately 2,000 foot-candles — to bloom reliably. A dry rest of about six weeks in autumn is generally needed to trigger flowering; under sufficiently high light and periodic dry spells the plant can flower multiple times per year. Because it is a trash-basket orchid with active mycorrhizal associations, it breaks down growing medium faster than most epiphytic orchids. Yellowish leaf coloration under high light is normal and reflects CAM photosynthesis; very green leaves indicate insufficient light.
