Pheidochloa Proc. Roy. Soc. Queensland 56: 20 (1944).

Derivation:. From Greek pheidos (sparing) and chloe (grass), referring perhaps to the delicate habit.

Taxonomic revisions, nomenclatural references:. S.T.Blake, Proc. Roy. Soc. Queensland 56: 11–22 (1944).

Key references (keys and floras):. M.Lazarides, Tropical Grasses S.E. Asia 164 (1980); B.K.Simon, Key to Australian Grasses 144 (1993); D.Sharp and B.K.Simon, AusGrass (2002); K.Mallet (ed.), Flora of Australia 44B: Poaceae 3: 175–176 (2005).

W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (553).

Native. 2 species, from Australia & New Guinea. 1 species in Australia, NT and Qld.

Habit. Slender annual, tufted. Leaf blades narrow. Ligule a fringe of hairs.

Inflorescence. Inflorescence a single raceme or paniculate (a raceme or depauperate panicle of few spikelets), an open panicle with branches ending in single spikelets.

Spikelets. Spikelets laterally compressed, 2 flowered, with 2 or more fertile florets, solitary, pedicelled; with rachilla terminating in a floret. Fertile spikelets disarticulating above glumes, with a distinctly elongated rachilla internode between glumes (glabrous).

Glumes. Glumes unequal (upper glume twice the length of lower glume), exceeding florets, (the longer) long relative to adjacent lemmas (much longer), hairless, pointed, awnless, keeled, similar (herbaceous-membranous). Lower glume 7 nerved. Upper glume 7 nerved.

Florets. Fertile florets 2 (similar). Lemmas similar in texture to glumes to decidedly firmer than glumes, not becoming indurated (thinly cartilaginous, often purplish), entire at apex, pointed, awned, without a germination flap, 7 nerved, hairy. Awns 1, apical, non-geniculate (purple), straight (bristle-like), about as long as body of lemma to much longer than body of lemma. Palea relatively long, 2 nerved. Callus long, pointed. Stamens 1. Grain small, linear, longitudinally grooved (concavo-convex), compressed dorsiventrally. Hilum long-linear. Embryo small, with one scutellum bundle.

Kranz Anatomy. C4, biochemical type NADP-ME (P. gracilis).

Habitat. In damp sandy heaths.

Classification. Micrairoideae; Eriachneae.

Notes. The spikelets are usually cleistogamous (Clayton and Renvoize, 1986). The genus is allied to Eriachne in the tribe Eriachneae, which has previously been placed with the subfamilies Panicoideae and Arundinoideae, but recent cladistic research based on molecular data suggest it belongs in neither. Until further data is available it is placed as Incertae Sedis (Kellogg pers. comm.).

Types Species. P. gracilis S.T.Blake.

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

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