Annuals Dictionary: Exacum
Gentian family
Gentianiaceae
Ecks’a-kum. A genus of 20 species of herbs or subshrubs from the Old World tropics, the species below grown for ornament.
Description
Leaves opposite, mostly stalkless or very short-stalked, without marginal teeth. Flowers mildly fragrant, in forked cymes, the calyx 4- to 5-parted. Corolla more or less twisted, its lobes usually 5 and blunt or pointed. Stamens 4-5, attached to the throat of the corolla.
How to Grow
Seeds need light and temperatures of 60-65° F (15.5-18.5° C) to germinate. Start indoors 8 weeks before last frost and set out 2 weeks after last frost. Grow in moist, well-drained soil. Good as a pot plant in light to moderate shade. Prefers warm weather.
Exacum affine
Persian Violet . 1-2 ft. (30-60 cm) high. Flowers bluish to mauve, in. (13 mm) wide, the corolla lobes pointed. South Yemen. Cultivar ‘Atrocaeruleum’ has dark lavender flowers. Biennial grown as a tender annual.