Commemorating Jean de la Ruelle (1474–1537) of Soissons, French botanist and physician, author of De Natura Plantarum (1536).
Perennial herbs, shrubs and subshrubs. Leaves opposite, entire, sometimes stalkless. Flower clusters axillary or terminal and branched, occasionally solitary. Calyx deeply divided into 5 sepals. Flower tube funnel-shaped. Stamens 4, in 2 unequal pairs, fused to the tube. Fruit a cylindrical to clubshaped capsule, containing 4-10 seeds that become mucilaginous when wet.
Grown mostly as indoor plants for the attractively coloured foliage and flowers.
The most widely grown species is R. makoyana hort. Closon, Trailing Velvet Plant (Monkey Plant), from Brazil; it has satiny leaves to about 7 cm long, purple below and with silvery veins. The flowers are carmine in winter and it is ideal for hanging baskets. R. macrantha Nees, Christmas Pride, also from Brazil, is occasionally grown for the showy, red-veined, lavender flowers and leaves with grooved veins.
Tip cuttings in summer.
Upright herb with bracts shorter than the sepals; fertile stamens 4.
About 150 species from tropical America, Africa, Asia, and temperate N America.
Source: (2002). Acanthaceae. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.