Habit and leaf form. Herbs; bearing essential oils, or without essential oils (?); resinous, or not resinous (?). Perennial. Leaves basal and cauline. Plants with a basal concentration of leaves. Mesophytic. Leaves small to medium-sized; alternate; ‘herbaceous’; petiolate; more or less sheathing. Leaf sheaths with free margins. Leaves gland-dotted, or not gland-dotted (?); aromatic, or foetid, or without marked odour (?); simple; not peltate; pulvinate, or epulvinate (?). Leaf blades entire; pinnately veined, or palmately veined (?). Leaves with stipules (?); without a persistent basal meristem. Stem anatomy. Nodes multilacunar, or tri-lacunar (?). Secondary thickening developing from a conventional cambial ring, or anomalous (?); from a single cambial ring.
Reproductive type, pollination. Fertile flowers hermaphrodite, or functionally male (occasionally). Unisexual flowers present, or absent. Plants hermaphrodite, or andromonoecious (occasionally). Male flowers with pistillodes (ovary rudimentary). Entomophilous.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in umbels. Inflorescences compound. The terminal inflorescence unit cymose, or racemose (?). Inflorescences terminal, or leaf-opposed; the peduncle bearing pedicellate flowers and three rays; rays flattened, swollen at apex, bearing pedicellate flowers; with involucral bracts (and with involucels). Involucral bracts 6, in 2 whorls of 3; involucel of 3 bractlets at outer margin of apex of each ray. Inflorescences pseudanthial, or not pseudanthial (depending on interpretation). Flowers pedicellate; bracteate; small; regular to somewhat irregular (?); 5 merous (except for the gynoecium); cyclic; tetracyclic, or tricyclic. Free hypanthium absent. Perianth with distinct calyx and corolla (but the calyx very reduced), or petaline (calyx teeth lacking); 5, or 10 (if calyx interpreted as present); 2 -whorled, or 1 -whorled; isomerous; white. Calyx present to absent; when detectable, 5; 1 -whorled; gamosepalous (much reduced); persistent. Corolla 5; 1 -whorled; polypetalous; valvate; unequal but not bilabiate, or regular (?); white. Corolla members entire. Androecium 5. Androecial members free of the perianth; all equal to markedly unequal (?); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; oppositisepalous; inflexed in bud. Anthers dehiscing via longitudinal slits; introrse; tetrasporangiate. Fertile gynoecium present, or absent (male and sterile flowers). Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium syncarpous; synovarious; inferior. Ovary plurilocular; 2 locular. Gynoecium median. Epigynous disk present. Gynoecium stylate. Styles 2; free (disc prominent, surrounding base of each style, stylopodium absent); apical. Stigmas wet type; non-papillate; Group IV type. Placentation axile, or apical (?). Ovules 1 per locule, or 2 per locule (usually two, but one abortive ?); pendulous; epitropous; non-arillate; anatropous.
Fruit and seed features. Fruit non-fleshy; a schizocarp. Mericarps 2 (suborbicular to reniform in outline, distinctly flattened laterally, surface tuberculate-rugose, ribs indistinct). Seeds endospermic. Endosperm oily. Embryo well differentiated. Cotyledons 2. Embryo achlorophyllous; straight. Seedling. Germination phanerocotylar.
Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia.
Additional characters Petals inflexed.