Trachymene Rudge

Scientific Description

Family Apiaceae.

Includes Uldinia.

Habit and leaf form. Herbs; bearing essential oils, or without essential oils (?); resinous, or not resinous (?). Annual, or biennial, or perennial; plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves. Helophytic, or mesophytic. Leaves small to medium-sized; alternate; ‘herbaceous’; petiolate to sessile; gland-dotted, or not gland-dotted (?); aromatic, or foetid, or without marked odour (?); simple; pulvinate, or epulvinate (?). Leaf blades dissected; 3-lobed to palmatisect; pinnately veined, or palmately veined. Leaves without stipules; without a persistent basal meristem. Leaf anatomy. Hairs present, or absent. 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’. Inflorescence few-flowered, or many-flowered. Flowers in umbels. Inflorescences simple. The terminal inflorescence unit cymose, or racemose (?). Inflorescences terminal, or leaf-opposed; with involucral bracts. Involucral bracts often shortly connate towards the base. Flowers bracteate; small; regular; 5 merous (except for the gynoecium); cyclic; tetracyclic, or tricyclic. Free hypanthium absent. Perianth with distinct calyx and corolla (but the calyx reduced), or petaline (apparently, the calyx lobes minute); 5, or 10; 2 -whorled, or 1 -whorled; isomerous; white, or cream, or yellow, or pink, or blue. Calyx when detectable, 5; 1 -whorled; gamosepalous; persistent. Corolla 5; 1 -whorled; polypetalous; imbricate; regular; white, or cream, or yellow, or pink, or blue. Petals elliptic to obovate. Corolla members entire (apex obtuse, not incurved). Androecium 5. Androecial members free of the perianth; all equal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; oppositisepalous; inflexed in bud. Anthers oblong to circular 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 a prominent, disc-like stylopodium crowning the ovary); 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; hairy, or not hairy; spinose (bristly), or not spinose; a schizocarp. Mericarps (1–)2 (with obtuse or winged dorsal 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. Not endemic to Australia.

Economic uses, etc. Ornamental plant.