Chamaexeros Benth.
Fl.Austral. 7:110 (1878)
Name Status: Current
Scientific Description
J. Gathe,
Friday 3 October 2008
Family Dasypogonaceae.
Habit and leaf form. Herbs (medium, caespitose, tufted). Perennial (graminoid habit). Leaves basal. Plants with a basal concentration of leaves (more or less acaulescent), or with neither basal nor terminal concentrations of leaves; rhizomatous (short). Pachycaul. Mesophytic, or xerophytic. Leaves small to large; alternate (or ‘indeterminate’: crowded, terminal rosette, dense 2-ranked tufts); spiral, or distichous; leathery, or modified into spines, or ‘herbaceous’; sessile; sheathing. Leaf sheaths not tubular; with free margins. Leaves simple. Leaf blades entire; flat; acicular, or linear; linear (gradually tapered to the apex); parallel-veined; without cross-venules; sheathing. Leaves without stipules. Leaf blade margins scarious and often becoming lacerated, or white membranous, or fimbriate. Vegetative anatomy. Plants without silica bodies. Leaf anatomy. Hairs absent. Extra-floral nectaries absent. Stem anatomy. Secondary thickening absent.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes, or in panicles. Inflorescences scapiflorous, or not scapiflorous; axillary; cymose panicles. Flowers pedicellate; bracteate (short, imbricate, scarious); ebracteolate; small; regular; 3 merous; cyclic; pentacyclic. Perigone tube present, or absent. Hypogynous disk absent. Perianth of ‘tepals’; 6; 2 -whorled; isomerous; petaloid; similar in the two whorls, or different in the two whorls; cream, or yellow; fleshy, or non-fleshy. Androecial members definite in number. Androecium 6. Androecial members free of the perianth, or adnate (adnate to the base of the perianth); all equal; free of one another; 2 -whorled. Androecium exclusively of fertile stamens. Stamens 6 (in 2 whorls); all more or less similar in shape; diplostemonous; 3 hypogynous and alternate with the inner segments, 3 on inner segments. Anthers dorsifixed; versatile; dehiscing via longitudinal slits; introrse. Pollen shed as single grains. Gynoecium 3 carpelled. The pistil 3 celled. Carpels isomerous with the perianth. Gynoecium syncarpous; eu-syncarpous; superior. Ovary plurilocular; 3 locular. Gynoecium stylate. Styles 1; attenuate from the ovary, or from a depression at the top of the ovary; apical. Stigmas 1; 1 - lobed, or 3 - lobed. Placentation axile. Ovules 2 per locule; non-arillate; anatropous to campylotropous.
Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal. Seeds endospermic. Embryo well differentiated. Testa without phytomelan.
Additional characters Pollen grains sulculate.
Keys to Chamaexeros Benth.
The Western Australian Genera and Families of Flowering Plants
TD Macfarlane, L Watson & NG Marchant
Taxonomic Literature
Wheeler, J.R. Marchant, N. G. Lewington, Margaret Graham, Lorraine Western Australian Herbarium (2002). Flora of the south west : Bunbury - Augusta - Denmark. Volume 1 : Introduction, keys, ferns to monocotyledons. ABRS and W.A. Herbarium in association with UWA Press. Canberra.
Macfarlane, T.D., Western Australian Herbarium (1994). Chamaexeros longicaulis (Dasypogonaceae), a new species from Walpole, south western Australia, with additional notes on Chamaexeros. Dept. of Conservation and Land Management. Como, W.A.
Australia. Bureau of Flora and Fauna (1986). Flora of Australia. Volume 46. Iridaceae to Dioscoreaceae. Australian Govt. Pub. Service. Canberra.
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