Lycium L.

Scientific Description

Common name. Boxthorns. Family Solanaceae.

Habit and leaf form. Shrubs; resinous, or not resinous. Plants spiny. Stem internodes solid. Helophytic to xerophytic. Leaves alternate (usually clustered); spiral; ‘herbaceous’, or leathery; petiolate, or sessile; non-sheathing; simple; epulvinate. Leaf blades entire; elliptic to obovate; pinnately veined; cross-venulate. Leaves without stipules. Leaf blade margins entire. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present (sparsely), or absent; glandular hairs present. Extra-floral nectaries absent.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous.

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; in fascicles (or clusters). The terminal inflorescence unit cymose. Inflorescences axillary, or leaf-opposed; flowering confined to spur shoots. Flowers pedicellate; ebracteate; ebracteolate; small to medium-sized; regular to somewhat irregular; somewhat zygomorphic. The floral asymmetry involving the perianth and involving the androecium. Flowers 4 merous, or 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present; intrastaminal. Perianth with distinct calyx and corolla; 8, or 10; 2 -whorled; isomerous. Calyx present; 4–5 (uneven); 1 -whorled; gamosepalous; campanulate, or cupuliform to cyathiform (to ellipsoid); unequal but not bilabiate, or bilabiate; persistent; more or less non-accrescent. Corolla present; 4–5; 1 -whorled; gamopetalous. Corolla lobes markedly shorter than the tube. Corolla imbricate; funnel-shaped; regular; white, or cream, or blue (creamy white to lilac). Corolla lobes elliptic to ovate. Androecial members definite in number. Androecium 4–5. Androecial members adnate; markedly unequal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 4–5. Staminal insertion near the base of the corolla tube, or in the throat of the corolla tube. Stamens all inserted at the same level; becoming exserted, or remaining included; not didynamous, not tetradynamous; all more or less similar in shape; isomerous with the perianth; oppositisepalous (towards the base of the corolla tube, in the throat). Filaments appendiculate, or not appendiculate; hairy (basally). Anthers separate from one another; dorsifixed; dehiscing via longitudinal slits; introrse; bilocular; tetrasporangiate. Pollen shed in aggregates, or shed as single grains. Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary plurilocular; 2 locular. Gynoecium oblique. Ovary sessile. Gynoecium stylate. Styles 1; attenuate from the ovary; apical. Stigmas 1; 2 - lobed (L); capitate. Placentation axile. Ovules 20–50 per locule (numerous); non-arillate; anatropous, or hemianatropous.

Fruit and seed features. Fruit fleshy; indehiscent; a berry; 20–100 seeded (numerous). Seeds endospermic. Endosperm oily, or not oily. Seeds compressed. Cotyledons 2. Embryo curved (or annular: curved through more than a semicircle).

Etymology. From the Greek for "buckthorn"; in Latin lycium, name used by Pliny for the medicinal juice obtained from Rhamnus lycioides, believed to be native of Lycia in Asia Minor.