Glycine Willd.

Scientific Description

Family Papilionaceae. Phaseoleae.

Sometimes included in Leguminosae.

Habit and leaf form. Herbs, or herbaceous climbers; not resinous. Plants unarmed. Perennial. Leaves cauline. Plants with neither basal nor terminal concentrations of leaves. Self supporting, or climbing (or prostrate); the climbers stem twiners, or scrambling. The twiners twining anticlockwise. 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; not gland-dotted; compound; pulvinate; ternate. Leaves pinnately trifoliolate, or palmately trifoliolate. Leaves imparipinnate. Leaflets 3; 1.5–7.5 cm long. Lateral leaflets opposite. Leaflets minutely stipellate (the stipels persistent); pulvinate; narrowly ovate, or ovate, or obovate, or linear; cuneate at the base, or oblique at the base, or rounded at the base; flat; without lateral lobes. Leaflet margins flat. Leaf blades dorsiventral; pinnately veined, or palmately veined; cross-venulate. Mature leaf blades adaxially scabrous, or pubescent; abaxially scabrous, or pubescent. Leaves with stipules. Stipules intrapetiolar; free of the petiole; free of one another; scaly, or leafy; caducous, or persistent (small). Leaf blade margins entire; not prickly; flat. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present; glandular hairs absent; complex hairs absent. Branched hairs absent. 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; in racemes, or in panicles. Inflorescences simple (seemingly of genuine racemes). The terminal inflorescence unit racemose (seemingly, at least usually). Inflorescences terminal, or axillary (mostly); mostly pedunculate, more or less contracted racemes without nodal swellings. Flowers pedicellate to sessile; bracteate. Bracts deciduous (caducous). Flowers (bi-) bracteolate. Bracteoles persistent (small, keeled, at the base of the calyx). Flowers small; very irregular; zygomorphic. The floral asymmetry involving the perianth and involving the androecium. Flowers papilionaceous (imbricate-descending); basically 5 merous; tetracyclic. Floral receptacle developing a gynophore to with neither androphore nor gynophore. Free hypanthium present, or absent. Hypogynous disk present; intrastaminal. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed; toothed. Calyx lobes markedly shorter than the tube to about the same length as the tube. Calyx imbricate; exceeded by the corolla; bilabiate (the lobes of the upper lip connate for about half their length); neither appendaged nor spurred; non-fleshy; persistent; non-accrescent; with the median member anterior. Calyx lobes ovate, or triangular. Epicalyx present (representing the bracteoles), or absent. Corolla present; 5; 1 -whorled; appendiculate, or not appendiculate. Standard not appendaged (or scarcely so — basally subauriculate). Corolla partially gamopetalous. 4 of the petals joined. The joined petals anterior (and lateral). The wings of the corolla obovate and adherent to the keel; not laterally spurred. Standard ‘normally’ developed; emarginate; not sericeous. Keel conspicuously exceeded by the wings; not long-acuminate/beaked (blunt); neither coiled nor spiralled; not bent and beaked. Corolla imbricate (descending); glabrous abaxially; glabrous adaxially; white, or purple, or blue; deciduous; non-accrescent. Petals clawed and sessile. Androecial members definite in number. Androecium 10. Androecial members free of the perianth; markedly unequal (the filaments alternately long and short); coherent; 2 - adelphous (the tenth, posterior stamen becoming free of the tube with age). The staminal tube free from the keel petals. Androecial members 1 -whorled. Androecium exclusively of fertile stamens. Stamens 10; all more or less similar in shape; diplostemonous; both opposite and alternating with the corolla members; filantherous. Anthers separate from one another to connivent; all alike; dorsifixed; 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 short, slender, slightly (in) curved. Style hairy but not bearded, or glabrous. Stigmatic tissue terminal. Carpel 2–10 ovuled (‘several’). Placentation marginal (along the ventral suture). Gynoecium median (the placenta posterior, on the ventral suture). Ovary subsessile. Stigmas capitate. Ovules not differentiated; pendulous to ascending; biseriate; arillate; anatropous, or campylotropous to amphitropous, or hemianatropous.

Fruit and seed features. Fruit aerial, or subterranean and aerial; 10–30 mm long; subsessile; non-fleshy; variously hairy; not spinose. The fruiting carpel dehiscent; a legume. Pods much elongated; not triangular; straight, or curved; not beaked; not becoming inflated; somewhat compressed; irregularly constricted, or not constricted between the seeds; more or less transversely septate between the seeds; wingless; not internally hairy. Valves of the dehisced pod not twisted. Fruit 1 celled; elastically dehiscent. Dispersal unit the seed. Fruit 2–4(–5) seeded, or 1 seeded (subterranean pods often one seeded). Seeds non-endospermic; not mucous; not compressed; small; arillate (the aril scalelike); wingless. Cotyledons 2; accumbent. Embryo curved, or bent. Testa hard; non-operculate; with tubercles (and alveolate), or smooth (muricate or alveolate); homogeneous in colour. Micropyle zigzag, or not zigzag. Seedling. Germination phanerocotylar.

Special features. Calyx limb 5 lobed. Upper lip of calyx lobed; 2 lobed. Lower lip of calyx lobed; 3 lobed.

Geography, cytology, number of species. Holarctic, Paleotropical, Neotropical, Cape, and Australian. Native of Australia. Endemic to Australia and not endemic to Australia. 2n=40, X=20; ploidy levels recorded 2. A genus of about 10 species; 9 species in Western Australia; G. albicans, G. arenaria, G. lactovirens, G. tomentella, G. ‘sp A’; 3 endemic to Western Australia.