Centotheca

Centotheca Nouv. Bull. Sci. Soc. Philom. Paris 2: 189 (1810).

Derivation:. From Greek kenteo (to prick) and theke (box), alluding to the prickly glumes.

Taxonomic revisions, nomenclatural references:. Monod de Froideville, Blumea 19: 57–60 (1971).

Key references (keys and floras):. G.Bentham, Flora Australiensis 7: 640–641 (1878); E.E.Henty, Manual Grasses New Guinea 47 (1969); M.Lazarides, Tropical Grasses S.E. Asia 153–154 (1980); B.K.Simon, Key to Australian Grasses 84 (1993); D.Sharp and B.K.Simon, AusGrass (2002).

W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (246).

Native. 4 species, from tropical Africa, Asia, Australia, Polynesia. 2 species in Australia, Qld. Also New Guinea and Malesia.

Habit. Perennial, rhizomatous or tufted. Leaf blades broad (to lanceolate, narrow at base). Ligule an unfringed membrane.

Inflorescence. Inflorescence paniculate or of spicate main branches, an open panicle with branches ending in single spikelets, open.

Spikelets. Spikelets laterally compressed, more than 2 flowered, with 2 or more fertile florets, solitary, pedicelled; with naked rachilla extension. Fertile spikelets disarticulating above glumes (usually) or falling with glumes, with a distinctly elongated rachilla internode between glumes.

Glumes. Glumes unequal, shorter than adjacent lemmas, pointed, awnless, similar (membranous to herbaceous). Lower glume 3–5 nerved. Upper glume 3–5 nerved.

Florets. Fertile florets (1–)2–3. Lemmas not becoming indurated, entire at apex to incised (obtuse to emarginate), mucronate, 9 nerved, hairy (the upper lemmas with reflexed bristles which act as a dispersal device), 1 keeled. Palea 2 nerved. Distal incomplete florets usually 1. Lodicules when present, 2. Stamens 1–3. Grain small, compressed laterally. Hilum short. Embryo small.

Kranz Anatomy. C3.

2n = 24, 2 ploid.

Habitat. Forests. Shade species.

Classification. Centothecoideae.

Notes. A homogeneous genus of barely distinct species. The lemma bristle serves as a dispersal device (Clayton and Renvoize, 1986).

Types Species. C. lappacea (L.) Desv.

Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Old World Tropics.

AVH 2011

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith