Schoenolaena Bunge

Scientific Description

Family Apiaceae.

Habit and leaf form. Slender, erect, rush-like herbs; bearing essential oils, or without essential oils (?); resinous, or not resinous (?). Perennial. Leaves basal (usually), or cauline. Rhizomatous. Helophytic. Leaves small to very large; alternate; ‘herbaceous’, or leathery (?); 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; pulvinate, or epulvinate (?). Leaf blades entire; solid; terete. Leaves with stipules, or without 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. Unisexual flowers absent. Plants hermaphrodite. Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in umbels, or in heads. Inflorescences compound. The terminal inflorescence unit cymose, or racemose (?). Inflorescences terminal and axillary; pedunculate; with involucral bracts; pseudanthial, or not pseudanthial (?). Flowers pedicellate to subsessile; bracteate. Bracts chartaceous, rigid, surrounding the flower heads, longer than the flowers. Flowers small; regular to somewhat irregular (?); 5 merous (except for the gynoecium); cyclic; tetracyclic. Free hypanthium absent. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous; white. Calyx 5; 1 -whorled; gamosepalous; distinctly lobed (lobes peltate); persistent. Calyx lobes circular to reniform with a cordate to sagittate base. Corolla 5; 1 -whorled; polypetalous; valvate; unequal but not bilabiate, or regular (?); white. Petals narrowly ovate. Corolla members entire (apex long). 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 oblong in outline; dehiscing via longitudinal slits; introrse; tetrasporangiate. 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 to partially joined (their bases thickened into large glands); 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 (with 5 narrow ribs). Seeds endospermic. Endosperm oily. Embryo well differentiated. Cotyledons 2. Embryo achlorophyllous; straight. Seedling. Germination phanerocotylar.

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.

Additional characters Petals inflexed.