Coriaria Niss. ex L.

Shrubs (rarely perennial herbs with herbaceous stems) or small trees. Roots with nodules with nitrogen fixing bacteria. Innovations in flushes from perulate apical buds. Branches 4-angular, ridges alternating; xylem with broad medullary rays. Leaves generally small, sessile or subsessile, with a narrow joint at base, simple, entire, cordate-ovate to lanceolate, acute, decussate, or (not in Malesia) in whorls, phyllotaxis of the lateral branches mostly showing as pseudo-distichous; blades palmately 3-9-curvi-nerved, net-veined, those sustaining side-branches often of somewhat different shape. Stipules absent (but see note). Racemes terminal or axillary. Flowers in the axils of small bracts, greenish or reddish, actinomorphic, hypogynous, polygamous, i.e., bisexual or functionally unisexual (both male and female flowers with rudiments of the other sex). Pedicel slender, bracteoles absent. Perianth 5-merous; sepals 5, imbricate, persistent, ovate; petals 5, alternate, shorter than the sepals, keeled inside, accrescent, becoming more or less fleshy, each enveloping a carpel in fruit. Stamens 10, in two whorls, free, or those opposite the petals adnate to the keel of the petal; filaments filiform; anthers exserted, ellipsoid or sagittate, papillose or smooth, 2-celled, opening lengthwise. Carpels 5-10(-12), free, one-celled, the basal part adnate to a central conical receptacle, each with a slender distinct papillose style. Ovules one per carpel, pendulous, anatropous, with the micropyle directed upwards. Pseudo-fruit consisting of hard-walled, laterally compressed achenes, more or less enclosed by the fleshy-accrescent petals, each achene subtended on each side by half of the adjoining petal. Seed compressed, without an aril, testa thin, endosperm scanty or none; embryo straight.

Uses Rich in tannin, used locally for tanning and black-dye. The flowers and fruits contain a narcotic, poisonous substance, coriariin. Some Coriaria species (e.g. the Mediterranean C. myrtifolia L., some New Zealand species, and also C. papuana) possess root nodules with nitrogen-fixing properties. As these species often grow in pioneering situations, such as lava fields and roadsides, they may have a place in planting programmes for erosion control in wet scree country (Daly et al. 1972). Coriaria nepalensis (India) is one of the food plants of the silk moth. References: Ambasta (ed.) Useful plants of India 1986 142 Daly, G.T., B.E. Smith & S. Chua Proc. New Zeal. Ecol. Soc. 19 1972 65-74 Watt, G. The commercial products of India 1908 1012