Habit and leaf form. Trees, or shrubs, or herbs, or lianas (rarely); bearing essential oils, or without essential oils. Leaves well developed (usually), or much reduced (scale-like), or absent. Herbs annual, or perennial; plants with neither basal nor terminal concentrations of leaves. Self supporting, or climbing (a few). Mesophytic, or xerophytic. Leaves alternate, or whorled; when alternate, spiral; ‘herbaceous’, or leathery, or membranous; petiolate; non-sheathing; simple. Leaf blades entire; pinnately veined; cross-venulate. Leaves without stipules. Leaf blade margins entire. Leaves without a persistent basal meristem. Stem anatomy. Nodes unilacunar. Secondary thickening developing from a conventional cambial ring, or anomalous.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Floral nectaries present, or absent. Entomophilous. Pollination mechanism conspicuously specialized, or unspecialized.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’, or solitary (rarely); in racemes, or in spikes, or in heads. The terminal inflorescence unit cymose. Inflorescences terminal, or axillary. Flowers bracteate; bracteolate; small; very irregular; medianly zygomorphic. The floral asymmetry involving the perianth and involving the androecium. Flowers ‘pseudo-papilionaceous’; cyclic; pentacyclic. Free hypanthium absent. Hypogynous disk present, or absent. Perianth with distinct calyx and corolla; 8, or 10; 2 -whorled; isomerous, or anisomerous. Calyx 5; 1 -whorled; more or less polysepalous; imbricate; unequal but not bilabiate (outer three members small and herbaceous, usually sepal-like, inner two (wings) larger, sometimes petal-like); persistent, or not persistent; with the median member posterior. Corolla 3, or 5 (the two lateral petals, when present, rudimentary); 1 -whorled; polypetalous, or gamopetalous; unequal but not bilabiate (the anterior (keel) petal boat-shaped, usually crested, clawed; the 2 posterior petals (wings) adnate at the base to the keel petal); white, or blue, or purple. Androecium 8. Androecial members adnate (to the upper petals); coherent; 1 - adelphous (the filaments entirely connate or free for part of their length); 1 -whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present, 2. Stamens 8 (usually), or 6. Anthers basifixed; dehiscing via short slits (appearing like apical pores); bilocular; bisporangiate (by reduction), or tetrasporangiate. Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary plurilocular; 2 locular. Gynoecium median; stylate. Styles 1 (curved or hooked, dilated at the apex); simple; apical. Stigmas 1, or 2 (stigmas apical or lateral); dry type; non-papillate; Group II type. Placentation axile. Ovules 1 per locule; pendulous; epitropous; with ventral raphe; arillate, or non-arillate; anatropous, or hemianatropous.
Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule (compressed, thin to coriaceous, sometimes winged). Capsules loculicidal. Seeds ovoid or obloid; endospermic, or non-endospermic. Endosperm oily. Seeds arillate; conspicuously hairy, or not conspicuously hairy; without a tuft of hairs. Cotyledons 2. Embryo chlorophyllous (2 species); straight. Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, biochemistry. Aluminium accumulation not found.
Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, Queensland, and New South Wales.