Family Papilionaceae. Bossiaeae.
Habit and leaf form. Shrubs. Plants unarmed. Mesophytic, or xerophytic. Leaves minute to medium-sized; alternate; spiral, or distichous; not imbricate; petiolate; non-sheathing; compound; pulvinate; ternate. Leaves pinnately trifoliolate. Leaves imparipinnate. Leaflets 3; not stipellate; pulvinate. Leaf blades dorsiventral, or isobilateral. Leaves with stipules. Stipules intrapetiolar; free of the petiole; scaly; caducous. Leaf blade margins entire. Leaves without a persistent basal meristem. Stem anatomy. Secondary thickening developing from a conventional cambial ring.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous, or ornithophilous.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in racemes. The terminal inflorescence unit racemose. Inflorescences terminal, or leaf-opposed. Flowers bracteate. Bracts deciduous. Flowers (bi-) bracteolate (but no series of subtending scales). Bracteoles deciduous. Bracteoles not adnate to the receptacle. Flowers minute to medium-sized; very irregular; zygomorphic; resupinate, or not resupinate. The floral asymmetry involving the perianth, or involving the perianth and involving the androecium. Flowers papilionaceous (imbricate-descending, with the posterior petal outside and forming a flag (‘standard’)); basically 5 merous. Floral receptacle developing a gynophore (the ovary stipitate); usually more or less cupular. Free hypanthium present, or absent. Hypogynous disk present; intrastaminal; annular. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; (5) lobed. Calyx lobes markedly shorter than the tube, or about the same length as the tube, or markedly longer than the tube. Calyx imbricate, or valvate; exceeded by the corolla; bilabiate (the two posterior lobes connate into a two-toothed lip, the anterior lobes narow, subequal); persistent; with the median member anterior. Epicalyx absent. Corolla present; 5; 1 -whorled; appendiculate, or not appendiculate. Standard not appendaged. Corolla partially gamopetalous. 2 of the petals joined (the two ventral petals connivent to form the ‘keel’?). The joined petals of the papilionate corolla anterior. The wings of the corolla free from the keel; not laterally spurred. Standard ‘normally’ developed. Keel conspicuously exceeded by the wings; not long-acuminate/beaked (blunt, incurved); neither coiled nor spiralled; not bent and beaked. Corolla imbricate (descending); yellow and purple; persistent, or deciduous. Petals clawed. Androecial members definite in number. Androecium 10. Androecial sequence determinable, or not determinable. Androecial members free of the perianth; all equal, or markedly unequal; coherent (into an adaxially split sheath); 1 - adelphous. The staminal tube free from the keel petals. Androecial members 1 -whorled (even though diplostemonous). Androecium exclusively of fertile stamens. Stamens 10; all more or less similar in shape; diplostemonous; both opposite and alternating with the corolla members. Anthers separate from one another, or connivent; all alike (all dorsifixed and with a perceptible, brown connective, but alternately smaller); 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 (in-) curved, or bent. Style glabrous. Stigmatic tissue terminal. Carpel 2–3 ovuled. Placentation marginal (along the ventral suture). Gynoecium median (the placenta posterior, on the ventral suture). Ovary stipitate. Ovules pendulous to ascending; biseriate; arillate; anatropous, or campylotropous to amphitropous, or hemianatropous.
Fruit and seed features. Fruit aerial; long stipitate; non-fleshy; hairy, or not hairy. The fruiting carpel dehiscent; a legume. Pods somewhat elongated (obliquely oblong-rhombic or falcate); not triangular; beaked; not becoming inflated; more or less flat; not constricted between the seeds; not transversely septate; winged to wingless (margined beyond the adaxial sutural nerve). Valves of the dehisced pod not twisted. Fruit 1 celled. Dispersal unit the seed. Fruit 2–3 seeded. Seeds endospermic, or non-endospermic; not mucous; compressed, or not compressed; small to medium sized; arillate (the aril hooded, caplike). Cotyledons 2; accumbent. Embryo curved to bent (the radicle inflexed). Testa non-operculate. Micropyle zigzag, or not zigzag.
Physiology, biochemistry. Aluminium accumulation not found. Photosynthetic pathway: C3.
Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia, South Australia, Queensland, New South Wales, Victoria, Australian Capital Territory, and Tasmania. 2n=16. A genus of 2 species; 1 species in Western Australia.