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Plant Highlight: Bulbine latifolia
The genus Bulbine is a fairly large group in the Asphodelaceae, with 84 species listed in the Monocotyledons volume of the Illustrated Handbook of Succulent Plants (2020). Most of the species are perennials with succulent leaves, though a few are annuals. Quite a few have tuberous roots, and such species often are dormant for part of the year, producing a new set of leaves when their growing season arrives. The majority of the species occur in the southern and western parts of South Africa, but some occur farther north in Africa, and 7 species occur in Australia.
One of the largest of the Bulbine species is Bulbine latifolia, which has an extensive distribution in eastern South Africa. It is evergreen, with stemless rosettes up to about 2½ feet in diameter (76 cm). Plants are often single-headed, but they may sometimes form a clump of several rosettes. The smooth green leaves are up to 1.3 feet long (40 cm), and up to 2.4 inches wide at the base (6 cm), tapering gradually to the pointed tip. There are many shallow grooves that run lengthwise along the leaf surfaces, imparting a faintly striped appearance. Though the margins lack conspicuous teeth, they have a minute fringe, visible on close inspection. The leaves are quite fleshy, and they are easily broken. The upper surface is somewhat channeled, often more so in the upper portion, and the mature leaves usually arch outward.
While Bulbine latifolia is listed as spring-flowering, in cultivation at the Ruth Bancroft Garden it is in flower for much of the year, typically taking a break for a few months in the summer. A rosette may have numerous inflorescences in bloom simultaneously, with each one rising to a height of up to 40 inches or more (1 m). The flower stalk is slender and smooth, and it is topped by a narrowly conical raceme bearing many bright yellow flowers, each with 6 tepals*. The flowers have a diameter of .3 to .8 inch (7.5 to 20 mm), opening widely and facing outward (sometimes slightly angled upward). The six stamens surrounding the central pistil have many wispy hairs along their filaments (the stalks of the stamens, which hold aloft the pollen-bearing anthers). This makes them look like tiny feather boas, and this is a defining character of Bulbine flowers in general. A pollinated flower gives way to a small, rounded seed capsule, and when this matures and dries, it splits open to spill the small black flattened seeds.
Like most succulents, Bulbine latifolia wants good drainage, and although it gets mostly summer rainfall in habitat, it does not mind getting winter rainfall. It is drought-tolerant, but it has a somewhat limited tolerance for cold. It will easily take temperatures down to freezing or a little below, but dips down to the mid-twenties Fahrenheit (-5°C) or below can do damage. At the Ruth Bancroft Garden, we grow plants beneath the canopy of a tree, with the overhead branches providing frost protection. The eaves of a house can perform the same function. This species can be grown in sun or light shade, but it does not do as well in deep shade.
*In families such as the Asphodelaceae, where the flowers do not have clearly distinguished sepals and petals, the term “tepals” is used.