Deciduous or evergreen, armed or unarmed, shrubs or small trees, rarely
scandent. Leaves alternate, subopposite or fascicled, petiolate, penninerves,
entire or dentate; stipules minute, free, persistent or deciduous. Inflorescence
axillary, solitary cymes or fascicles, rarely panicles or thyrses. Flowers 5- or
4-merous, bisexual or polygamo-dioecious. Calyx lobes 4-5, triangular-ovate,
erect or spreading; tube urceolate. Petals 4-5 or absent, inserted on the margin
of calyx tube, cucullate or flat, shortly clawed. Stamens 4-5; filaments very
short; anthers dehiscing longitudinally. Disc thin, tilling the calyx tube. Ovary
(2-) 3 or 4-celled, ovoid; styles 3-4 -cleft, rarely 2-cleft about half the length;
stigma obtuse, papillose. Drupes with 2-4, free, 1-seeded stones, globose,
encircled at base by calyx tube; pyrenes horny or cartilaginous, indehiscent
or dehiscing inwardly. Seeds obovate; testa membranous or crustaceous, smooth
or furrowed on the back; raphe dorsal, ventral or lateral; albumen fleshy;
cotyledons flat or with recurved margins.
America, Europe, Asia, often rare in tropics; ca 150 species, 11 in India.
Notes.
Most of the Indian species are confined to the Himalayas except
R. purandharensis and R. wightii. which are confined to peninsular India.
Indian species are found in wooded or open forests in Himalaya and
Western Ghats, usually at altitudes ranging between 600 to 3000 m.
KEY TO THE SPECIES
1a. Erect shrubs or trees, sometimes rambling
2
b. Prostrate shrubs
10
2a. Plants unarmed
3
b. Plants armed (unarmed in R. procumbens)
8
3a. Leaves pubescent or tomentose
4
b. Leaves glabrous
6
4a. Petals absent; fruits surrounded at base only by rim of the
calyx
