Common name
Coolah Grass

Derivation
Panicum L., Sp. Pl. 55 (1753) & Gen. Pl. 5th edn, 29 (1754); Panicum: old Latin name for common millet (Setaria italica), from Latin panis (bread).

coloratum- coloured unusually, especially with reference to lemmas.

Published in
Mant. Pl. 1: 30 (1767).

Habit
Perennial, tufted. Rootstock evident. Cataphylls absent, or present. Stolons absent. Culms erect or decumbent, 15–120 cm tall, 6–12-noded. Mid-culm internodes glabrous. Mid-culm nodes glabrous or pubescent (rarely). Lateral branches sparsely branched. Leaf-sheaths glabrous on surface or pilose or hispid. Leaf-sheaths outer margin glabrous or hairy. Leaf-sheath auricles absent. Ligule an eciliate or a fringed membrane. Leaf-blade base simple or truncate or broadly rounded or cordate. Leaf-blades linear, (3–)10–30 cm long, (2–)4–10 mm wide. Leaf-blade surface smooth, glabrous or pilose. Leaf-blade apex acute or acuminate.

Inflorescence
Inflorescence compound, a panicle, exserted. Panicle open, oblong, 4–30(–40) cm long, evenly furnished or with spikelets clustered towards branch tips. Primary panicle branches appressed or ascending or spreading, 7–15 cm long, bearing 30–250 fertile spikelets on each lower branch. Panicle branches bearing congested spikelets or distant spikelets.

Spikelets
Spikelets solitary. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret male, upper fertile, without rhachilla extension, elliptic or ovate, dorsally compressed, obtuse or acute or acuminate, 2–3.2 mm long, falling entire. Rhachilla internodes brief up to lowest fertile floret.

Glumes
Glumes dissimilar, thinner than fertile lemma. Lower glume ovate, not gibbous, 0.7–1 mm long, 25–33% of length of spikelet, membranous, 1(–3)-nerved. Lower glume lateral nerves absent or obscure. Lower glume apex acute, muticous or mucronate. Upper glume elliptic or ovate, 2–3.2 mm long, equalling spikelet, membranous, 7–9-nerved. Upper glume apex acute.

Florets
Basal sterile floret 1, with palea. Lemma of lower sterile floret similar to upper glume, ovate, 2–3.2 mm long, 100% of length of spikelet, membranous, 7–9-nerved, acute, mucronate. Fertile lemma oblong, dorsally compressed, 1.5–2.5 mm long, indurate, pallid, glossy. Lemma surface smooth. Lemma margins involute. Lemma apex obtuse, muticous or mucronate. Palea involute, indurate.

Continental Distribution:
Africa, Temperate Asia, Tropical Asia, Australasia, Pacific, North America, South America.

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

Western Australia: Gardner, Dampier, Drummond. Queensland: Leichhardt, Darling Downs. New South Wales: North Coast, Central Coast, Southern Tablelands, North-Western Slopes, Central-Western Slopes, South-Western Slopes, North-Western Plains, South-Western Plains. Victoria: Murray Mallee, Riverina, Midlands.

Classification. (GPWG 2001):
Panicoideae: Paniceae

Notes
Introduced. Native to tropical Africa but now widely introduced as a forage species. In tropical and subtropical wet sclerophyll forests, dry sclerophyll forests, tropical and subtropical sub-humid woodlands, temperate sub-humid woodlands, semi-arid shrub woodlands, and shrub steppe shrublands. Flowers throughout the year. Vegetative characteristics of the species are highly variable. Diagnostic features are the presence of the male lower floret, glabrous cataphylls, and the lower glume less than 1/3 the spikelet length.