Bulbine is a genus of approximately 80 species of succulent and semi-succulent plants in the family Asphodelaceae (subfamily Asphodeloideae, order Asparagales), formerly classified within Liliaceae. The genus is named for the bulb-like tubers characteristic of many of its members.
The genus is highly variable in growth form, encompassing shrubs, weedy perennials, dwarf geophytes, and soft annuals. Plants typically have soft, fleshy leaves and tuberous roots or a thickened caudex. In this way they resemble Haworthia and Aloe, but are distinguished by their softer, non-rigid foliage. Many of the smaller species produce compact, dome-shaped tubers. Dormancy usually runs from late spring through autumn, during which the leaves die back, the roots contract into the caudex, and aboveground parts wither.
Flowers are borne in lax or compound racemes and are most commonly yellow, with distinctively bearded stamens that set the genus apart from relatives. Some species bear white, orange, or pink flowers. Propagation is mostly by seed, though species that produce multiple heads or offsets can also be propagated by cuttings.
The genus is centered in southern Africa, with species diversity concentrated in South Africa and Namibia. A small number of species extend into tropical Africa, and a few occur in Australia and Yemen. Bulbine frutescens, a shrubby, orange-flowered perennial from South Africa, is the most widely cultivated member and a common garden and landscaping plant in warm climates.
Etymology
The name Bulbine derives from the bulb-shaped tubers found in many species of the genus. The word traces to the Greek bolbos, meaning bulb or bulbous root.
Distribution
Bulbine is found chiefly in southern Africa, with the greatest diversity in South Africa and Namibia. A small number of species extend into tropical Africa, while a few outlying species occur in Australia and Yemen.
Ecology
Most Bulbine species are adapted to seasonally dry conditions, undergoing a pronounced dormancy period from late spring to autumn. Dwarf geophyte species rely on dome-shaped tubers to survive dry seasons underground. The genus includes both annuals and long-lived perennials occupying a range of habitats from rocky outcrops to open scrubland in southern Africa.
Cultivation
Several Bulbine species are cultivated as ornamentals, particularly B. frutescens, which is grown widely in warm-climate gardens. Dormancy is a key aspect of cultivation: most species rest from late spring to autumn, with foliage dying back and roots contracting. Propagation is primarily by seed; species that form multiple heads or offsets can also be propagated from cuttings.
