Common name
Russell River Grass

Derivation
Paspalum L., Syst. Nat. 10th edn, 855 (1759); from the Greek paspalos (a kind of millet).

paniculatum- from the Latin panus (thread), -ula (diminutive) and -ata (possessing). Inflorescence open with thread-like pedicels.

Published in
Syst. Nat. 10th edn, 855 (1759).

Habit
Perennial, tufted. Cataphylls present. Stolons absent. Culms erect, 30–215 cm tall, 2–7-noded. Mid-culm nodes pubescent. Lateral branches sparsely branched. Leaf-sheaths hairy. Leaf-sheaths outer margin glabrous. Leaf-sheath auricles absent. Ligule an eciliate membrane, 2–3 mm long. Leaf-blades 8–50 cm long, 6–30 mm wide. Leaf-blade surface smooth, hairy.

Inflorescence
Inflorescence compound, a panicle of racemes. Racemes few or numerous, 7–60, spreading, unilateral, 4–12 cm long, 0.3–0.6 mm wide, bearing 90–180 fertile spikelets on each. Central inflorescence axis 5–20(–30) cm long. Rhachis wingless or narrowly winged, angular, 0.5 mm wide. Spikelet packing regular, 4-rowed.

Spikelets
Spikelets in pairs. Pedicels 0.3–1.2 mm long. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret sterile, upper fertile, without rhachilla extension, orbicular, dorsally compressed, plano-convex, obtuse, 1.3–1.4 mm long, falling entire.

Glumes
Glume 1 (the lower absent or obscure), thinner than fertile lemma. Upper glume orbicular, 1.3–1.4 mm long, 100% of length of spikelet, hyaline or membranous, dark brown, 3-nerved. Upper glume surface puberulous. Upper glume margins eciliate. Upper glume apex obtuse.

Florets
Basal sterile floret 1, without significant palea. Lemma of lower sterile floret similar to upper glume, elliptic, 1.3–1.4 mm long, 100% of length of spikelet, membranous, 3-nerved, puberulous, obtuse. Fertile lemma orbicular, gibbous, hemispherical, 1–1.4 mm long, indurate, pallid. Lemma surface striate. Lemma margins involute. Lemma apex obtuse. Palea involute, cartilaginous or indurate. Anthers 0.5–0.8 mm long.

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

Australian Distribution:
Queensland, New South Wales.

Queensland: Cook, North Kennedy, South Kennedy, Wide Bay, Moreton. New South Wales: North Coast, North-Western Slopes.

Classification. (GPWG 2001):
Panicoideae: Paniceae

Notes
Introduced. A weedy species which prefers moist sites from forest margins to marshy areas. Flowers Feb.–Aug.