Streptocarpus

The Streptocarpus genus forms part of the Gesneriaceae or African violet family. They are commonly called African violets or African primroses.

The plants are usually stemless annual, perennial or monocarpic herbs, although some subshrubs form part. A monocarpic plant flowers once before it dies.

The leaves may be either solitary or several in a basal rosette and when growing on stems, opposite or alternating. The leaves are often velvety and quilted.

The bisexual flowers are laterally symmetrical, growing in stalked cymes. There are small bracts below the flowers in some species, sometimes leaf-like. The tubular calyx ends in five lobes or is divided to the base.

The tubular corolla is funnel- or trumpet-shaped, ending in two lips, divided into two and three lobes respectively. The two stamens arising inside the corolla tube are usually included, cohering face to face. There is usually a nectary present in the form of an annulus (ring), cup or disc. The superior ovary is cylindrical, ovoid or cone-shaped comprising one or two locules.

The fruit is a cylindrical or conical capsule that dehisces. The Streptocarpus name is derived from the Greek words streptos meaning twisted and karpos meaning fruit, referring to the often spirally twisted, corkscrew shape of the dehisced, cylindrical, fruit capsule husk. The tiny, ellipsoid, brown seeds are usually without endosperm. The seeds are very small and light, distributed by wind. 

The Gesneriaceae family consists of more than 140 genera, represented by only the one genus, Streptocarpus, in South Africa. Most of the others are found in Asia. Streptocarpus consists of about 125 species, about 45 of them found in southern Africa.

The plant pictured is Streptocarpus formosus (Leistner, (Ed.), 2000; Manning, 2009).