Steinchisma

Steinchisma* Bull. Bot. [Geneve] 1: 220 (1830).

Derivation:. From Greek steinos (narrow) and chasma (yawning), alluding to the gaping lower floret.

Syn: Fasciculochloa B.K.Simon & C.M.Weiller.

Taxonomic revisions, nomenclatural references:. B.K.Simon and C.M.Weiller, Austrobaileya 4: 369–379 (1995), as Fasciculochloa; B.K.Simon, Austrobailaya 5: 583–584 (1999).

Key references (keys and floras):. D.Sharp and B.K.Simon, AusGrass (2002) and as Cliffordiochloa p.p.

W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (459).

Naturalised. 5 species, from New World. 1 species in Australia, Qld.

Habit. Perennial, tufted. Leaf blades narrow, parallel veined. Ligule a fringed membrane.

Inflorescence. Inflorescence paniculate, an open panicle with branches ending in single spikelets, open, non-digitate.

Spikelets. Spikelets laterally compressed or subterete, 2 flowered, with 1 fertile floret, solitary or paired (obscurely), pedicelled. Fertile spikelets morphologically conventional, with lower incomplete floret(s), elliptic, adaxial (with lower glume against rachis) (obscurely), laterally compressed or subterete, falling with glumes.

Glumes. Glumes unequal, shorter than spikelet, shorter than adjacent lemmas, hairy or hairless, glabrous, awnless, non-keeled, without a median keel-wing. Lower glume 0.6 times length of upper glume, much shorter than half length of lowest lemma, relatively smooth, 3 nerved. Upper glume 3–5 nerved.

Florets. Lower incomplete floret(s) sterile. Lemmas resembling upper glume, awnless, 5 nerved, exceeding fertile lemmas, similar in texture to fertile lemmas, not becoming indurated. Palea of lower incomplete florets becoming conspicuously hardened and enlarged laterally (becoming leathery). Fertile florets 1. Lemmas elliptic, similar in texture to glumes, smooth, not becoming indurated, entire at apex, blunt, muticous, 2 nerved, having flat margins not tucked into palea. Palea entire, textured like lemma, indurated (slightly), glabrous. Lodicules 2. Stamens 1. Disseminule a naked seed. Grain small, pale brown, ellipsoid, glabrous. Hilum short. Embryo large.

Kranz Anatomy. C3.

Classification. Panicoideae; Paniceae.

Notes. The genus is difficult to distinguish from Panicum until the fruit ripens and the palea develops its characteristic thickening (Clayton and Renvoize, 1986).

Types Species. S. hians (Elliot) Nash.

Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Naturalised.

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