Hibiscus (Malvaceae)

This is one of the oldest plants cultivated by mankind, for its edible fruit. For example, Hibiscus esculentus bears a fruit which has been used extensively as a vegetable in Africa, Asia, Central and Latin America. Known as gombo or lalo on Réunion Island, it resembles somewhat courgette  (zucchini). It is eaten in salads when young, cooked when mature. More than 30,000 varieties are known.  Flowers remain twisted until they briefly open: for instance, they only last a single day in the species H. rosa sinensis. Bernard Shaw wrote: “The hibiscus is a flower to please, / Grown in a warm and temperate clime. / Reds, blues and whites do tease,/ With glowing colours so sublime.” Each flower has five sepals and five petals. The petals are often iridescent, which serves as a visual clue to in-sects such as bumblebees. The iridescence is due to the presence of a series of overlying cuticular striations that act as a diffraction grating. The five stamens are welded together into a long tube. The pistil often has five ovaries and a long style going through the tube of stamens. The flowering machinery of the hibiscus is most impressive in its frequent output. Leaves, often a deep green, are alternate, simple, ovate or lanceolate, with toothed or wavy edges. In many a folk culture, remedies draw on the hibiscus. For instance, teas made from the sepals of H. sabdariffa remedy hypertension.