Leucospermum is a genus of about 50 species of flowering plants in the family, Proteaceae. Most species are native to the Western Cape Province of South Africa, where they occupy a variety of habitats including scrub, forest, and mountain slopes. Two species occur outside of South Africa, with one each in Swaziland and Zimbabwe.
Typically, Leucospermums are evergreen shrubs. Some species are groundcovers and rarely are they small trees. The shrubs are usually neatly rounded in shape and free-flowering, bearing a flower head at the end of each branch. When not in flower, a character that differentiates Leucospermum from other members of the protea family, is the presence of 'toothed' leaves. The small indentations with raised edges, often red in color, occur along the margins or at least at the leaf tips. The leaves are spirally arranged and are tough and sometimes leathery.
Unlike the genus Protea, where it is the brightly-colored bracts that surround the flowers, the actual floral parts of Leucospermum are what catch the eye. The wonderful display of color in the spring can last for four months or longer. The flowers are produced in dense inflorescences which have large numbers of prominent styles, each thickened at the apex to form the stigma. This inspires the common name, "pincushion," reminding one of pins stuck into a pincushion.
Leucospermum, the scientific name, means "white seed" and was given because the fruit, technically a nut, is very smooth and shiny, and usually whitish-grey. These oval to round fruits ripen much more quickly than those of most other members of the protea family and are released upon ripening. In their native habitats, Leucospermums are myrmecochorous, meaning there is an ant-plant mutualism which disperses the seeds. Mutualism is a symbiotic relationship that mutually benefits the ants and the plants. The seeds have an appendage called an elaiosome which attracts ants and causes them to carry the seeds to their nests, where the elaiosomes are eaten. This disperses the seeds while keeping them underground, safe from fires and predators.
Pincushions have become an increasingly significant export cut-flower crop in several countries apart from its native South Africa. There are many named cultivars, and intensive breeding programs in South Africa and Hawaii are producing spectacular hybrids with disease-resistant characteristics. Cultivars available range from dramatic groundcovers to brilliant long-stemmed flowers produced on large shrubs. Cultivars grown at SFBG include: 'Scarlet Ribbon', 'Spider', 'Tango', 'Veldfire', 'California Sunshine', 'Yellow Bird', and 'Helderfontein'.
IN BLOOM CONTRIBUTORS: Joanne Taylor, Mona Bourell and Marc Johnson.