Dunbaria Wight & Arn.

Scientific Description

Family Papilionaceae. Phaseoleae.

Sometimes included in Leguminosae.

Habit and leaf form. Herbaceous climbers (with annual stems and perennial, tuberous rootstock); resinous. Plants unarmed. Perennial. Leaves cauline. Plants with neither basal nor terminal concentrations of leaves; tuberous. Climbing; stem twiners. Twining anticlockwise. Mesophytic. Leaves small to 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 (but conspicuously glandular, the glands golden); aromatic, or without marked odour; compound; pulvinate; ternate. Leaves pinnately trifoliolate. Leaves imparipinnate. Leaflets 3; 0.7–2 cm long. Lateral leaflets opposite. Leaflets stipellate (the stipels persistent, minute). Leaflets without swollen, glandlike stipels. Leaflets pulvinate; ovate (lanceolate); rounded at the base; flat; without lateral lobes. Leaflet margins flat. Leaf blades dorsiventral; cross-venulate. Mature leaf blades abaxially woolly (minutely tomentose). Leaves with stipules. Stipules intrapetiolar. Stipules not peltate. Stipules free of the petiole; free of one another; scaly, or leafy; persistent. Leaf blade margins entire; not prickly; flat. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present; glandular hairs present; complex hairs absent. Branched hairs absent. Stem anatomy. Secondary thickening absent, or developing from a conventional cambial ring, or anomalous.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers present. Plants hermaphrodite. Pollination mechanism conspicuously specialized.

Inflorescence and flower features. Flowers mostly solitary; not crowded at the stem bases; axillary. Inflorescences mostly 1-flowered, representing a reduced raceme. Flowers pedicellate; bracteate (the bracts small). Bracts deciduous. Flowers bracteolate to ebracteolate (the bracteoles minute and obscure). Bracteoles deciduous. Flowers small to medium-sized; very irregular; zygomorphic. The floral asymmetry involving the perianth and involving the androecium. Flowers papilionaceous (imbricate-descending); basically 5 merous; tetracyclic. Floral receptacle with neither androphore nor gynophore. Free hypanthium present, or absent. Hypogynous disk present; intrastaminal. Perianth with distinct calyx and corolla; 9, or 10; 2 -whorled; isomerous, or anisomerous. Calyx present; 4, or 5 (the upper lip being only minutely bifid); 1 -whorled; gamosepalous; lobed; toothed (the lobes acuminate). Calyx lobes markedly shorter than the tube to about the same length as the tube. Calyx imbricate; exceeded by the corolla; bilabiate; neither appendaged nor spurred; non-fleshy; persistent; non-accrescent; with the median member anterior. Corolla present; 5; 1 -whorled; appendiculate (auriculate). Standard appendaged (auriculate). Corolla partially gamopetalous. 2 of the petals joined, or 4 of the petals joined. The joined petals anterior. The wings of the corolla adherent to the keel, or free from the keel; not laterally spurred. Standard ‘normally’ developed; markedly emarginate; not sericeous. Keel conspicuously exceeded by the wings, or about equalling the wings; not long-acuminate/beaked (blunt); neither coiled nor spiralled; not bent and beaked (its apex incurved). Corolla imbricate (descending); glabrous abaxially; glabrous adaxially; yellow; deciduous; non-accrescent. Petals clawed. Androecial members definite in number. Androecium 10. Androecial sequence not determinable. Androecial members free of the perianth; all equal, or markedly unequal; coherent; 2 - adelphous (the posterior stamen free of the rest, whose filaments are united below); 1 -whorled. Androecium exclusively of fertile stamens. Stamens 10; distinctly dissimilar in shape (the posterior member thickened and geniculate); diplostemonous; both opposite and alternating with the corolla members; filantherous. Anthers separate from one another, or connivent; all alike; dorsifixed (near the base); versatile; dehiscing via longitudinal slits; latrorse, or introrse; tetrasporangiate. 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 hooked, or bent (inflexed). Style terete (filiform or slightly thickened). Style hairy but not bearded, or glabrous. Stigmatic tissue terminal. Carpel 5–8 ovuled. Placentation marginal. Gynoecium median (the placenta posterior, on the ventral suture). Ovary sessile. Ovary summit hairy, the hairs not confined to radiating bands (shortly hairy and glandular). Stigmas capitate. Ovules pendulous to ascending; biseriate; arillate; anatropous, or campylotropous to amphitropous, or hemianatropous.

Fruit and seed features. Fruit aerial; 28–50 mm long; stipitate; non-fleshy; not spinose. The fruiting carpel dehiscent; a legume. Pods much elongated; not triangular; straight; not becoming inflated; more or less flat, or somewhat compressed; not constricted between the seeds; transversely septate between the seeds (the septa spongy); wingless. Valves of the dehisced pod not twisted. Fruit 1 celled; elastically dehiscent. Dispersal unit the seed. Fruit 5–8 seeded. Seeds non-endospermic; not mucous; compressed; small; arillate (the aril long, cleft). Cotyledons 2; accumbent. Embryo curved, or bent. Testa hard; non-operculate; smooth; conspicuously colour-patterned (mottled). Micropyle zigzag, or not zigzag.

Special features. Calyx limb 4 lobed (ostensibly), or 5 lobed (the posterior lip being apically bifid). Upper lip of calyx entire to lobed; 2 lobed. Lower lip of calyx lobed; 3 lobed.

Geography, cytology, number of species. Native of Australia. A genus of about 15 species; 1 species in Western Australia; D. singuliflora F. Muell.