Deyeuxia gravida
C.G.Taylor & N.G.WalshWeakly caespitose annual (perhaps more long-lived through sequential wet years), culms decumbent to ascending, to c. 60 cm long. Leaves soft-textured, rather flaccid, ± smooth to slightly scabrous; blade flat or weakly channelled, to c. 20 cm long and 3 mm wide; ligule obtuse, 1–3 mm long. Inflorescence a slender, contracted panicle with ±appressed branches, c. 2–15 cm long, 1.5–6 mm wide, often slightly interrupted. Spikelets 2.3–3.4 mm long, green at anthesis; glumes acute, sub-equal, scabrous along the keel, gaping about the lemma; lemma shorter or subequal to glumes, 1.9–2.9 mm long, ovoid, minutely to strongly scabrous along whole length and the nerves, hardly thickened, but the 5 nerves prominently raised, entire or microscopically 4-toothed at the apex, awned just above the callus; callus hairs not uniform with some reflexed, less than a quarter the length of the lemma; rachilla bristle absent. Awn 2.5–3.8 mm long, geniculate, twisted in lower part and typically exceeding lemma; palea 1.8–2.5 mm long, sub-equal to the or sometimes exceeding the lemma or, strongly 2-keeled and visible between lemma margins at maturity.
Known with certainty only from far south-western Victoria in the Cobboboonee and Lower Glenelg National Parks, with an outlying easterly occurrence in the Otway Ranges near Barongarook.The species is likely to occur in South Australia, but it is currently not known from there.
Deyeuxia gravida appears most closely related to D. quadriseta with which it shares characters of more or less cylindrical inflorescence, florets lacking an obvious rachilla extension and an awn inserted in the lower one-third of the lemma. It differs from D.quadriseta most significantly in the strongly nerved lemma and palea, and in the plump caryopsis that causes the palea to protrude as the caryopsis ripens. It differs further in the palea being often longer than the lemma, the more strongly scabrous surface of the lemma, and the non-uniform callus hairs.The lemma apex of D. quadriseta is typically 4-toothed, and sometimes conspicuously so with teeth approaching 1 mm long. The lemma apex of D. gravida is either entire or microscopically 4-toothed.
Taylor, C.G. & Walsh, N.G. (2024). Deyeuxia gravida (Poaceae: Agrostidae), a newly described species from Victoria, Australia. Muelleria 42: 40–48.