Common name
Nitgrass

Derivation
Gastridium P.Beauv., Ess. Agrostogr. 21, t. 6, fig. 6 (1812); diminutive of the Greek gaster (belly) referring to the basally swollen glumes.

phleoides- inflorescence a spike-like panicle as for phleum.

Published in
Kew Bull. 9: 375 (1954).

Habit
Annual, culms solitary or tufted. Culms erect or decumbent, 10–60 cm tall. Leaf-sheath auricles absent. Ligule an eciliate membrane, 2–7 mm long. Leaf-blades 2.5–15 cm long, 1–4 mm wide, surface scaberulous.

Inflorescence
Inflorescence solid, a panicle. Panicle contracted or spiciform, lanceolate to oblong, dense, 4–18 cm long, 0.5–1.5 cm wide. Primary panicle branches appressed. Panicle branches bearing congested spikelets.

Spikelets
Spikelets solitary. Pedicels linear, scaberulous, tip pyriform. Fertile spikelets 1-flowered, comprising 1 fertile floret, with a barren rhachilla extension, oblong or cuneate, laterally compressed, 4.3–5.5(–8) mm long, breaking up at maturity. Spikelets disarticulating below each fertile floret. Floret callus obtuse.

Glumes
Glumes persistent, similar, firmer than fertile lemma, shiny. Lower glume lanceolate, saccate, 4.3–5.5(–6) mm long, 110–150% length of upper glume, 100% of length of spikelet, membranous, 1-keeled, 1-nerved, midnerve scaberulous. Lower glume lateral nerves absent. Lower glume apex acuminate or attenuate. Upper glume lanceolate, saccate, 3.6–5 mm long, 300-400% of length of adjacent fertile lemma, membranous, much thinner above, 1-keeled, 1-nerved, midnerve scaberulous. Upper glume lateral nerves absent. Upper glume apex attenuate.

Florets
Fertile lemma elliptic or oblong, 1.1–1.5 mm long, cartilaginous, 5-nerved. Lemma surface pubescent or villous, hairy on back. Lemma apex erose, truncate, muticous or 1-awned. Median (principal) awn dorsal, arising 80% way up back of lemma, geniculate, 4–6(–8) mm long overall, not or scarcely exserted from spikelet, with a twisted column. Palea 100% of length of lemma, cartilaginous, 2-nerved. Rhachilla extension 50% length of fertile floret, pilose. Anthers 3, 1 mm long. Grain with adherent pericarp. Hilum punctiform.

Continental Distribution:
Africa, Temperate Asia, Australasia, Pacific.

Australian Distribution:
Western Australia, South Australia, New South Wales, Victoria.

Western Australia: Drummond, Dale. South Australia: Flinders Ranges, Eyre Peninsula, Northern Lofty, Murray, Southern Lofty, Kangaroo Island, South-eastern. New South Wales: Central Tablelands. Victoria: Wannon, Grampians, Midlands, Victorian Volcanic Plain.

Classification. (GPWG 2001):
Pooideae: Poeae

Notes
Introduced from the Mediterranean, now widely naturalised. Uncommon, a weed of disturbed areas preferring flat, low-lying sites or near watercourses. Flowers Oct.–Feb. Fruits unknown.