previous arrow
next arrow

Genus :


Family :



Herbs, subshrubs or shrubs, strongly aromatic, glabrous to villous, woody below. Leaves petiolate, opposite or whorled, toothed, pitted with minute glands. Inflorescence of 6 to 10-flowers in whorl arranged in terminal spiciform racemes, pedicel tip recurved. Bracts elliptic-lanceolate to broadly ovate, caducous. Calyx campanulate, deflexed, enlarged in fruits, upper lip broad, flat, decurrent, lower lip with 4 teeth, lateral 2 mucronate and middle 2 acuminate. Corolla lower lip hardly longer, declinate, entire. Stamens 4, declinate, exserted, filaments free, anther cells confluent. Disk entire or 4-lobed. Ovary 4-partite, styles bifid, lobes subulate or flattened. Nutlets 4, dry, smooth, basal scar small.

Key to the species

Serial Key Reference
1a. Fruiting calyx 0.6 cm or more long 2
1b. Fruiting calyx below 0.4 cm long 3
2a. Lower teeth of fruiting calyx longer than the upper O. basilicum
2b. Lower teeth of fruiting calyx shorter than the upper O. gratissimum
3a. Pedicels as long as calyx tube; flowers lax in whorles, calyx tube glabrous within O. tenuiflorum
3b. Pedicels much shorter than calyx tube; flowers dense in whorles, calyx tube hairy within O. americanum