Transactions of the Linnean Society of London, Botany 10 p301 (1810)
Name Status: Current
Friday 3 October 2008
Habit and leaf form. Herbs, or shrubs; bearing essential oils, or without essential oils (?); resinous, or not resinous (?). Plants unarmed. Herbs 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’, or leathery; petiolate; gland-dotted, or not gland-dotted (?); aromatic, or foetid, or without marked odour (?); simple, or compound; pulvinate, or epulvinate (?); when compound ternate. Leaf blades when simple entire, or dissected; flat; when simple/dissected, 3-lobed or repeatedly ternately divided; pinnately veined. Leaves without stipules. Leaf blade margins entire, or dentate. Leaves 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’ (usually), or solitary; in umbels. Inflorescences simple, or compound. The terminal inflorescence unit cymose, or racemose (?). Inflorescences terminal, or leaf-opposed; usually with 2–4 short rays and 1 or more flowers in the centre between the rays, umbellules with 1 or more ray bracts; with involucral bracts; pseudanthial (when bracts or ray bracts petal-like), or not pseudanthial. Flowers pedicellate, or sessile; bracteate; 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, or green to yellow. Calyx 5; 1 -whorled; gamosepalous; lobed (lobes similar in length to petals); persistent. Corolla 5; 1 -whorled; polypetalous; valvate; unequal but not bilabiate, or regular (?); white, or green to yellow. Corolla members entire (apex narrow). 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 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 2-lobed 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; a schizocarp. Mericarps 2 (with 5–9 ribs and rounded outer margin). 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, South Australia, Queensland, New South Wales, Victoria, Australian Capital Territory, and Tasmania.
Additional characters Petals inflexed.
Keys to Xanthosia Rudge
TD Macfarlane, L Watson & NG Marchant
Wheeler, J.R. Marchant, N. G. Lewington, Margaret Graham, Lorraine Western Australian Herbarium (2002). Flora of the south west : Bunbury - Augusta - Denmark. Volume 2 : Dicotyledons. ABRS and W.A. Herbarium in association with UWA Press. Canberra.
Hart, J.M. Henwood, M.J., Western Australian Herbarium (1998). Xanthosia eichleri, a new species of Apiaceae from Western Australia. Dept. of Conservation and Land Management. Como, W.A.
Keighery, G.J. (1989). Taxonomy of the Xanthosia fruticulosa group (Apiaceae). Council for Nordic Publications in Botany. Copenhagen.
Marchant, N. G. (1987). Flora of the Perth region. Part 1. Western Australian Herbarium. [South Perth].
Blackall, William E. Grieve, Brian J. (1980). How to know Western Australian wildflowers : a key to the flora of the extratropical regions of Western Australia. Part 3A. University of Western Australia Press. Nedlands, W.A.