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Plant Highlight: Albuca spiralis
By Brian Kemble
Family placement and area of occurrence
Albuca is a genus of bulbs, mostly African in origin, that have been placed in the Hyacinthaceae, or Hyacinth Family. In recent years, some authorities have accepted broader family circumscriptions, and they have treated the Hyacinthaceae as the subfamily Scilloideae within the Asparagaceae, or Asparagus Family. Whether treated as a family or as a subfamily, this group includes many familiar bulbs such as bluebells (in the genus Hyacinthoides), hyacinths (in the genus Hyacinthus) and grape hyacinths (in the genus Muscari).
The genus Albuca, as traditionally circumscribed, contains about 60 species*, found in Africa and also across the Red Sea in Arabia, with a concentration of species in the winter-rainfall region on the western side of southern Africa. Most of the species are on the small side, with narrow leaves and with racemes holding a modest number of flowers. In some species the open flowers face upwards, while in others they face downwards, but whichever way they are held, they all have flowers that are white or yellow, ususally with a green stripe down the middle of each tepal (note that the term “tepal” is used in place of “petal” for flowers that do not have clearly distinct sepals and petals). In most species, there are three widely spreading outer tepals, and three inner tepals that clasp the stamens and pistil, hiding these from view.
Several species of Albuca have spiraled leaves, and one of these is Albuca spiralis, whose name refers to this trait. It comes from the winter-rainfall region in western South Africa, from the arid Namaqualand area in the country’s northwest southward to Cape Town. In keeping with this, it is a winter grower, flowering in early spring, and then going dormant during the summer months.
About the plant
Albuca spiralis is a dwarf species, usually growing with the tops of the bulbs exposed. The bulbs are up to an inch in diameter (2.5 cm), and they may be solitary or grow as a small group. The bright green leaves of A. spiralis are held in a compact tuft, and they are up to 4⅓ inches long (11 cm), though their spiraling makes it is difficult to tell this from looking at a plant. They are very narrow, with a width of only about .04 inch (1 mm). At the base they are channeled on the upper side, but higher up they are nearly cylindrical, with only a groove to indicate the upper surface. Sometimes there is a noticeable fringe of tiny hairs , especially at the leaf bases, but in other cases this is not visible.
In nature, this species grows in sunny locations, and the leaves are typically tightly spiraled. However, plants grown in lower light levels may be less spiraled, and they may also be reluctant to flower.
About the flowers
The short inflorescence emerges in early spring, and it carries a modest number of nodding greenish-yellow flowers that are sweetly scented. As is usual in Albuca, the outer three tepals are spreading, and these are about .7 inch long (18 mm), yellow at the margins and dull green at the center. The inner three tepals are held close to the stamens and pistil, and these too are yellowish-green, with a daub of bright yellow at their tips. Though not visible, since they are clasped by the inner tepals, at the center of the flower there are six stamens and a pistil with a three-lobed stigma.
About the fruits
Solitary bees are apparently the primary pollinators of albucas, though their pollination biology has not been well studied. A successfully pollinated flower produces a rounded capsule, and within are three chambers containing the flat shiny black seeds. At maturity, the capsule splits open to release the seeds.
*Newer classifications include some of the species from the related genus Ornithogalum, enlarging the number of species to about 125.
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