Strychnos L.

Loganiaceae, E. A. Bruce and J. Lewis. Flora of Tropical East Africa. 1960

Morphology General Habit

Trees or shrubs, sometimes scrambling or climbing with spines or hooked tendrils

Morphology Leaves

Leaves decussate, entire, 3–7-nerved from near the base; stipules absent or represented by an interpetiolar ridge

Morphology Reproductive morphology Inflorescences

Cymes axillary or terminal, simple or panicled

Morphology Reproductive morphology Flowers Calyx

Calyx 4- or 5-lobed, sometimes very deeply

Morphology Reproductive morphology Flowers Corolla

Corolla campanulate or salver-shaped; lobes 4 or 5, valvate in the bud

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 4 or 5; filaments short but anthers usually exserted

Morphology Reproductive morphology Flowers Gynoecium Pistil

Ovary 2-locular; style moderately long, undivided; stigma usually capitate; ovules few to many

Morphology Reproductive morphology Fruits

Fruit a drupe or a berry with a hard rind

Morphology Reproductive morphology Seeds

Seeds few to numerous, flattened or globose; endosperm copious and hard; embryo small.

Loganiaceae, A. J. M. Leeuwenberg. Flora Zambesiaca 7:1. 1983

Morphology General Habit

Erect or climbing shrubs, lianas, or trees. Trees: usually less than 10 m. high (savanna spp.), 10–35(40) m. (forest spp.); trunk 10–100 cm. in diam.; without tendrils, often with arching branches (iS. usambarensis, S. xantha). Lianas with curled tendrils, solitary or arranged in 1–3 pairs above each other on short branches, in the axils of small bracts or — only if solitary — sometimes in the axils of ordinary leaves.

Morphology Stem

Branches armed with axillary or sometimes terminal simple straight or slightly recurved spines, unarmed, often lenticellate, rarely corky; branchlets terete, quadrangular, sometimes sulcate, especially when dry. Wood mostly hard, usually with bark–islets; bark mostly thin, smooth or less often rough, in lianas often with large lenticels, sometimes thick and corky (S. cocculoides).

Morphology Leaves Stipules

Stipules mostly reduced to an often ciliate and straight rim connecting the petiole–bases.

Morphology Leaves

Leaves opposite, sometimes decussate, or on the main axis sometimes ternate, those of a pair or whorl equal or subequal, petiolate or sometimes subsessile, mostly inserted on distinct leaf–cushions; blade variously shaped, orbicular to narrowly elliptic, mostly coriaceous, in the shade thinner, often larger, and more acute at the apex, entire; with 1–2(3) pairs of distinct secondary veins from or from above the base curved along the margin, usually not fully reaching the apex, anastomosing with the other veins or less often pinnately veined.

Morphology Reproductive morphology Inflorescences

Inflorescence terminal, axillary, or both, thyrsoid, 1–many–flowered, shorter or longer than the leaves, lax or congested, sometimes sessile.

Morphology Reproductive morphology Flowers

Flowers 4–5–merous, actinomorphic or with only sepals unequal.

Morphology Reproductive morphology Flowers Calyx

Calyx: sepals green or coloured approximately like the corolla, free or connate up to one–half of their length, equal, subequal, or sometimes unequal, imbricate, orbicular to linear, outside hairy or glabrous.

Morphology Reproductive morphology Flowers Corolla

Corolla rotate to salver–shaped, white to yellowish, greenish, pale green, or rarely orange or ochraceous, thin at the base, always more or less thickened towards the lobes, on both sides variously hairy, papillose, or glabrous, but inside at the base always glabrous, sometimes with a corona at the mouth; lobes valvate in the bud, triangular to oblong, acute or subacute, entire, erect to recurved.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens exserted or included, inserted at the mouth of or in the corolla tube; filaments glabrous or sometimes hairy; anthers introrse, orbicular to narrowly oblong, cordate, deeply so, or less often sagittate at the base.

Morphology Reproductive morphology Flowers Gynoecium Pistil

Pistil: ovary 2– or rarely 1–celled (S. mellodora, S. spinosa); stigma capitate, less often obscurely bilobed, or occasionally conical.

Morphology Reproductive morphology Flowers Gynoecium Ovary Placenta

In a one–celled ovary one basal placenta which is mostly globose, with few (S. mellodora) or many ovules (S. spinosa). In each cell of a 2–celled ovary one axial placenta with 2 to about 50 ovules, attached to the middle of the septum.

Morphology Reproductive morphology Fruits

Fruit a berry, 1–2–celled, globose or nearly so, mostly yellow to red, less often green when mature, sometimes blue–black (S. potatorum), immature often glaucous, glabrous, subtended by the persisting calyx, 0·8–18 cm. in diameter, 1–45–seeded. Pulp juicy, fleshy, often edible (S. cocculoides, S. madagascariensis, S. pungens, S. spinosa, and also in some small–fruited species). Wall thin and soft in small fruits, thicker and brittle in (mature) larger (very hard in nearly mature!!).

Morphology Reproductive morphology Seeds

Testa thick and osseous to very thin and membranaceous, rough and scabrid–pubescent (only when thick) or smooth and sericeous to glabrous. Seeds large, 0·5–3(5) cm. long, variably shaped, generally disc–shaped to subglobose. Endosperm horny, slightly diaphanous.

Morphology General Colleters

Sometimes some colleters above the bracts, on the base of the sepals, and near the base of the petioles.