Family Papilionaceae. Mirbelieae.
Sometimes included in Leguminosae.
Habit and leaf form. Shrubs (or undershrubs). Plants unarmed. Leaves cauline. Plants with neither basal nor terminal concentrations of leaves; to 0.3–1 m high. Leaves alternate; spiral; petiolate (the terminal leaflet always sessile), or subsessile to sessile (when ‘simple’); non-sheathing; simple, or compound; when compound, unifoliolate (sometimes detectably), or ternate, or pinnate, or palmate; when pinnate, imparipinnate. Leaflets not stipellate. Leaves with stipules (usually, small), or without stipules. Stipules intrapetiolar; free of one another; subulate or setaceous.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.
Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; when solitary, terminal, or axillary (rarely, in the upper axils). Inflorescence when flowers aggregated, few-flowered to many-flowered. Flowers in racemes, or in corymbs, or in fascicles, or in heads (headlike corymbs). Inflorescences simple. The terminal inflorescence unit when determinable, racemose. Inflorescences terminal (usually), or axillary (in the upper axils); shortly racemose, or flowers solitary or 2–3 together. Flowers pedicellate; bracteate (bracts small), or ebracteate; bracteolate (usually, the bracteoles small and usually in the middle of the pedicels), or ebracteolate; very irregular; zygomorphic. The floral asymmetry involving the perianth, or involving the perianth and involving the androecium. Flowers papilionaceous; tetracyclic. Floral receptacle developing a gynophore to with neither androphore nor gynophore (the ovary shortly stipitate or subsessile). Free hypanthium present, or absent. Hypogynous disk present; intrastaminal; annular. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; shortly gamosepalous; lobed. Calyx lobes markedly longer than the tube. Calyx valvate; exceeded by the corolla; regular (the lobes ‘all sub-similar’); non-fleshy; persistent; non-accrescent; with the median member anterior. Corolla present; 5; 1 -whorled; appendiculate, or not appendiculate. Standard not appendaged. Corolla polypetalous, or partially gamopetalous. 2 of the petals joined. The joined petals anterior (the keel members). The wings of the corolla free from the keel (oblong, often falcate, the keel broader); not laterally spurred. Standard ‘normally’ developed; entire, or emarginate. Keel conspicuously exceeded by the wings, or about equalling the wings, or conspicuously exceeding the wings; not long-acuminate/beaked; neither coiled nor spiralled; not bent and beaked. Corolla imbricate; yellow, or orange, or red, or pink, or purple, or brown. Petals shortly clawed. Androecial members definite in number. Androecium 10. Androecial sequence determinable, or not determinable. Androecial members free of the perianth; all equal to markedly unequal; free of one another; 1 -whorled. Stamens 10; all more or less similar in shape; diplostemonous; both opposite and alternating with the corolla members; filantherous. Anthers connivent; all alike; dorsifixed; 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. Style (in-) curved (filiform or slightly thickened distally). Style glabrous. Carpel (3–)4–25 ovuled (to ‘many’). Placentation marginal. Gynoecium median. Ovules funicled (the funicles elongated); biseriate.
Fruit and seed features. Fruit stipitate; non-fleshy. The fruiting carpel dehiscent; a legume. Pods globose, or somewhat elongated (ovoid or subglobose, often oblique); not triangular; straight; becoming inflated; not constricted between the seeds; not transversely septate; wingless. Fruit 1 celled. Dispersal unit the seed. Fruit 4–8 seeded (‘few’). Seeds not mucous; small; non-arillate. Embryo bent (radicle inflexed). Testa non-operculate.
Geography, cytology, number of species. Native of Australia. 2n = 18. A genus of about 25 species; 17 species in Western Australia (27 if Burtonia included).
Additional comments. Note that the ovule number of ‘4 or more’ encoded by Crisp and Weston (1995) apparently fails to account for their inclusion (following their 1987 paper) of Burtonia.