Spathia Fl. Northern Territory. 26 (1917).
Derivation:. From Greek spathe (blade), alluding to the prominent spathe.
Taxonomic revisions, nomenclatural references:. S.T.Blake, Papers Dept. Biol. University Qld 2(3): 46–50 (1944).
Key references (keys and floras):. M.Lazarides, Flora of Central Australia 494–495 (1981); J.C.Tothill and J.B.Hacker, Grasses of Southern Queensland 382–383 (1983); B.K.Simon, Key to Australian Grasses 159 (1993); D.Sharp and B.K.Simon, AusGrass (2002).
W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (593).
Native, endemic. 1 species, from Barkly Tableland of NT and adjacent parts of Qld. NT Qld.
Habit. Annual, tufted. Leaf blades narrow. Ligule a fringed membrane.
Inflorescence. Inflorescence of spicate main branches (of sessile or subsessile racemes), a spatheathe panicle, digitate, spatheate (with one broad, membranous spathe enclosing the inflorescence), racemes paired or in clusters, not in tight heads, a compound pseudo-inflorescence (up to 3 partial inflorescences) or not a compound pseudo-inflorescence. Spikelet-bearing axes racemes, with heteromorphic spikelets (the pedicellate spikelets less hairy, awnless), clustered (3–5), disarticulating at joints. Internodes disarticulating obliquely, densely long-hairy (with brown hairs).
Spikelets. Spikelets dorsally compressed, 2 flowered, with 1 fertile floret, awned, paired, sessile and pedicelled or subsessile and pedicelled, in pedicelled/sessile combinations; sessile spikelet with lower incomplete floret. Fertile spikelets falling with glumes.
Glumes. Glumes more or less equal, hairy (the hairs brown), awnless, dissimilar (the lower bicarinate and blunt, the upper cymbiform and pointed). Lower glume two-keeled, convex on back, 7–9 nerved. Upper glume 3 nerved.
Florets. Lower incomplete floret(s) sterile. Lemmas awnless, 0 nerved, less firm than fertile lemmas, not becoming indurated. Fertile florets 1. Lemmas stipe-like beneath the awn, less firm than glumes, not becoming indurated, entire at apex, awned, 0–1 nerved. Awns 1, apical, geniculate, hairless (glabrous), much longer than body of lemma. Palea absent. Callus blunt. Lodicules 2. Stamens 3. Grain small, compressed dorsiventrally. Hilum short. Embryo large. Pedicels free of rachis. Pedicelled spikelets present, similar in shape to sessile spikelet, sterile, with glumes (two), 1 floreted.
Kranz Anatomy. C4.
Habitat. Grassy plains. Species of open habitats.
Classification. Panicoideae; Andropogoneae.
Notes. The genus is distinguished by the spathe. It has plump Sorghum - like spikelets, but the internode tip and pedicelled spikelet callus suggest a derivation from Dichanthium (Clayton and Renvoize, 1986).
Types Species. S. neurosa Ewart & Archer.
Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Endemic.