Mucuna Adans.

Scientific Description

Family Papilionaceae. Phaseoleae.

Sometimes included in Leguminosae.

Habit and leaf form. (Sub-) shrubs, or lianas, or herbs; evergreen, or deciduous; not resinous. Plants unarmed. Perennial. Leaves cauline. Plants with neither basal nor terminal concentrations of leaves. Self supporting, or climbing; stem twiners, or scrambling. Mesophytic. Leaves medium-sized; not fasciculate; alternate; spiral, or distichous; not decurrent on the stems; ‘herbaceous’, or leathery; not imbricate; petiolate. Petioles wingless. Leaves non-sheathing; compound; pulvinate; ternate. Leaves pinnately trifoliolate. Leaves imparipinnate. Leaflets 3; stipellate; pulvinate; flat; with conspicuous lateral lobes to without lateral lobes (the laterals basally asymmetric). Leaflet margins flat. Leaf blades dorsiventral; cross-venulate. Leaves with stipules. Stipules intrapetiolar. Stipules not peltate. Stipules free of the petiole; free of one another; scaly, or leafy; caducous. Leaf blade margins entire; not prickly. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present; glandular hairs absent. Branched hairs absent. Urticating hairs absent (? — present on calyces and pods). Stem anatomy. Secondary thickening developing from a conventional cambial ring, or anomalous.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the disk.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; not crowded at the stem bases; 1–3 per axil. Inflorescences compound (flowers 1–3 per node); axillary; ‘racemose or umbelliform’, pseudo-racemes, subumbels or panicles. Flowers pedicellate; bracteate. Bracts deciduous. Flowers (bi-) bracteolate. Bracteoles deciduous. Bracteoles not adnate to the receptacle. Flowers small to large; very irregular; zygomorphic; resupinate, or not resupinate. The floral asymmetry involving the perianth and involving the androecium. Flowers papilionaceous; basically 5 merous; tetracyclic. Floral receptacle with neither androphore nor gynophore. Free hypanthium present, or absent. Hypogynous disk present; intrastaminal; of separate members to annular (the ligulate members connate around the base of the ovary). Perianth with distinct calyx and corolla; 9, or 10; 2 -whorled; isomerous, or anisomerous. Calyx present; 4 (the posterior members more or less completely connate), or 5; 1 -whorled; gamosepalous; four or five lobed; blunt-lobed. Calyx lobes markedly shorter than the tube, or about the same length as the tube. Calyx hairy (with stinging hairs); imbricate, or contorted; exceeded by the corolla; regular, or unequal but not bilabiate, or bilabiate; neither appendaged nor spurred; non-fleshy; persistent; non-accrescent; with the median member anterior. Corolla present; 5; 1 -whorled; appendiculate (the standard auriculate, the keel petals lobed). Standard appendaged (auriculate). Corolla partially gamopetalous. 2 of the petals joined, or 4 of the petals joined. The joined petals anterior (and lateral?). The wings of the corolla adherent to the keel (often), or free from the keel; not laterally spurred. Standard ‘normally’ developed (not reflexed); not sericeous. Keel about equalling the wings, or conspicuously exceeding the wings; long-acuminate and beaked to not long-acuminate/beaked (straight or incurved); neither coiled nor spiralled; not bent and beaked. Corolla imbricate (descending); green to white, or cream, or yellow, or white and red, or purple; not fleshy; deciduous; non-accrescent. Petals clawed. Androecial members definite in number. Androecium 10. Androecial sequence determinable, or not determinable. Androecial members free of the perianth; markedly unequal (the filaments alternately long and short); coherent (the filaments forming a staminal tube); 2 - adelphous (9+1, the vexillary member more or less free). The staminal tube free from the keel petals. Androecial members 1 -whorled. Androecium exclusively of fertile stamens (unless the disc-scales are regarded as staminodes, as by Dunlop et al). Stamens 10; distinctly dissimilar in shape; diplostemonous; both opposite and alternating with the corolla members. Anthers separate from one another, or connivent; dimorphic; alternately dorsifixed (the shorter, which are often bearded), or basifixed (the longer); versatile and non-versatile; dehiscing via longitudinal slits; latrorse, or introrse; tetrasporangiate. Pollen shed as single grains. Gynoecium 1 carpelled. The pistil 1 celled. Carpels reduced in number relative to the perianth. Gynoecium monomerous; of one carpel; superior. Carpel stylate; apically stigmatic. Style (in-) curved. Style hairy but not bearded (below). Stigmatic tissue terminal. Carpel 4–6 ovuled. Placentation marginal (along the ventral suture). Gynoecium median (the placenta posterior, on the ventral suture). Ovary sessile, or subsessile. Ovary summit hairy, the hairs not confined to radiating bands. Stigmas capitate. Ovules funicled; pendulous to ascending; biseriate; arillate; anatropous, or campylotropous to amphitropous, or hemianatropous.

Fruit and seed features. Fruit aerial; 60–150 mm long; stipitate, or subsessile, or sessile; non-fleshy; hairy (with stinging hairs); not spinose. The fruiting carpel dehiscent; a legume. Pods much elongated; not triangular; straight, or curved; not becoming inflated; more or less flat, or somewhat compressed; irregularly constricted, or not constricted between the seeds; transversely septate between the seeds (or ‘filled between the seeds’); winged, or wingless; when winged, 2 (along the margins); not internally hairy. Valves of the dehisced pod not twisted. Fruit 1 celled. Dispersal unit the seed. Fruit 2–6 seeded. Seeds non-endospermic; not mucous; small, or medium sized; arillate, or non-arillate; not conspicuously hairy. Cotyledons 2; accumbent. Embryo curved, or bent. Testa hard; non-operculate; smooth; homogeneous in colour, or conspicuously colour-patterned. Micropyle zigzag, or not zigzag. Seedling. Germination cryptocotylar.

Special features. Calyx limb 4 lobed, or 5 lobed. Upper lip of calyx entire to lobed; 1–2 lobed. Lower lip of calyx lobed; 3 lobed.

Geography, cytology, number of species. World distribution: pantropical. Native of Australia. Australian states and territories: Western Australia, Northern Territory, and Queensland. 2n=22. A genus of about 100 species; 5 species in Western Australia.