Common name
Barley Mitchell Grass
Cow Mitchell

Derivation
Astrebla F.Muell. ex Benth., Fl. Austral. 7: 602 (1878); from the Greek a (not) and streblos (twisted), in reference to the straight awns.

pectinata- from the Latin pecten (comb) and -ata (possessing). Inflorescence with spikes or racemes bearing a fanciful resemblance to a comb.

Published in
Fl. Austral. 7: 602 (1878).

Habit
Perennial, tufted. Cataphylls present. Rhizomes short. Basal leaf sheaths glabrous. Culms erect, 15–120 cm tall, 6–9-noded. Lateral branches branched, arising from lower culm. Ligule a fringed membrane. Leaf-blades 7–25 cm long, 2.7 mm wide, glaucous. Leaf-blade surface ribbed. Leaf-blade margins scaberulous. Leaf-blade apex filiform.

Inflorescence
Inflorescence solid, a raceme, embraced at base by subtending leaf. Racemes 1, unilateral, 3–13 cm long, 10–20 mm wide. Rhachis flattened, puberulous on surface. Spikelet packing broadside to rhachis, imbricate, regular, 2-rowed.

Spikelets
Spikelets pectinate, solitary. Pedicels oblong. Fertile spikelets 2-flowered or many flowered, comprising 2–4 fertile florets, with diminished florets at the apex, oblong, laterally compressed, 8–20 mm long, breaking up at maturity. Spikelets disarticulating above glumes but not between florets. Rhachilla internodes 0.5 mm long. Floret callus pilose.

Glumes
Glumes persistent, dissimilar, thinner than fertile lemma. Lower glume lanceolate or ovate, 7–14 mm long, 90–110% length of upper glume, chartaceous, much thinner on margins, 1-keeled, 5–9-nerved. Lower glume apex acuminate. Upper glume lanceolate or ovate, 8–13 mm long, 66–75% of length of adjacent fertile lemma, chartaceous, with membranous margins, 7–16-nerved. Upper glume apex acuminate.

Florets
Fertile lemma oblong, 3–5 mm long, 3–4 mm wide, coriaceous, much thinner above, 3-nerved (in the body). Lemma lateral nerves augmented by subsidiaries in lobes. Lemma surface villous. Lemma apex lobed, 3-fid, with outer lobes longer, with lanceolate lobes, incised 50–70% of lemma length, 1-awned. Median (principal) awn 6 mm long overall. Palea 4–6 mm long. Palea keels ciliate. Apical sterile florets resembling fertile though underdeveloped. Lodicules 2, cuneate, fleshy, truncate. Anthers 3, 0.9–1.6 mm long. Grain with adherent pericarp. Hilum elliptic.

Continental Distribution:
Australasia.

Australian Distribution:
Western Australia, Northern Territory, South Australia, Queensland, New South Wales.

Western Australia: Gardner, Fitzgerald, Hall, Giles, Fortescue, Ashburton, Carnarvon, Austin. Northern Territory: Victoria River, Barkly Tableland, Central Australia North, Central Australia South. South Australia: North-western, Lake Eyre, Gairdner-Torrens Basin, Flinders Ranges, Eastern. Queensland: Burke, South Kennedy, Leichhardt, Darling Downs, Gregory North, Gregory South, Mitchell, Warrego, Maranoa. New South Wales: Northern Tablelands, North-Western Slopes, North-Western Plains, South-Western Plains, North Far Western Plains.

Classification. (GPWG 2001):
Chloridoideae: Cynodonteae

Notes
Distributed across most of inland Australia between 15°S and 33°S (N of 28°S in W.A.), except the Great Sandy, Gibson and Great Victoria Deserts of W.A. This species is the dominant grass over most of the Barkly Tableland and headwaters of the Georgina R. in the N.T. with much smaller areas of dominance at the head of Sturt Ck and N of Mt Hay. Occurrences in W.A. and S.A. are restricted to relatively small pockets of cracking clay soils, for example, between ridges in hilly areas, in depressions and drainage lines. Through Qld and N.S.W. A. pectinata may become locally dominant but generally it is less abundant than A. lappacea or other perennial grasses. Associated taxa include other Astrebla species, Eragrostis setifolia, Eulalia aurea, Iseilema and Aristida; flowers after rain.
Astrebla pectinata is a vigorous perennial that persists under adverse conditions such as heavy stocking and drought. Pastures dominated by the species produce an abundance of fodder and thus are capable of maintaining large numbers of stock for long periods. They are particularly valuable in good seasons when associated short-lived grasses and forbs are prolific. At least one collection with a paniculate inflorescence has been made, the individual being out-breeding. Cleistogamy is common, and the species is remarkably uniform across its distribution.

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