Common name
Fine Armgrass

Derivation
Brachiaria (Trin.) Griseb., in C.F. von Ledebour, Fl. Ross. 4: 469 (1853). From the Latin brachium (arm), alluding to the manner of bearing the racemes.

reptans- from the Latin repo (crawl). Culms ascending from a creeping rhizome of runner.

Published in
Hooker's Icon. Pl. t. 3363: 3 (1938).

Common synonyms
Urochloa reptans (L.) R.D.Webster

Habit
Annual. Stolons present. Culms decumbent, 10–60 cm tall, rooting from lower nodes. Mid-culm internodes glabrous. Mid-culm nodes pubescent. Ligule a fringe of hairs. Leaf-blade base broadly rounded. Leaf-blades lanceolate, 1.5–8 cm long, 3–15 mm wide. Leaf-blade surface glabrous or hairy. Leaf-blade margins scabrous.

Inflorescence
Inflorescence compound, a panicle of racemes. Racemes 5–15, unilateral, 1–4 cm long, 0.1–0.5 mm wide. Central inflorescence axis 1–8 cm long. Rhachis wingless, angular, smooth on surface or scabrous on surface. Spikelet packing imbricate, irregular or regular, 2-rowed.

Spikelets
Spikelets in pairs. Pedicels ciliate, tip discoid. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret male, upper fertile, without rhachilla extension, elliptic or oblong, slightly dorsally compressed, acute, 1.5–2.2 mm long, falling entire. Rhachilla internodes brief up to lowest fertile floret.

Glumes
Glumes dissimilar, thinner than fertile lemma. Lower glume orbicular, clasping, 0.4–0.6 mm long, 15–25% of length of spikelet, hyaline, 0–1-nerved. Lower glume lateral nerves absent. Lower glume apex truncate. Upper glume ovate, 1.7–2.2 mm long, 100% of length of spikelet, membranous, 7-nerved. Upper glume surface glabrous. Upper glume apex acute, muticous.

Florets
Basal sterile floret 1, with palea. Lemma of lower sterile floret similar to upper glume, ovate, 1.7–2.2 mm long, 100% of length of spikelet, membranous, 5-nerved, glabrous, acute. Fertile lemma elliptic, 1–2 mm long, indurate. Lemma surface rugulose or rugose. Lemma margins involute. Lemma apex acute, mucronate. Palea involute, indurate, without keels.

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

Australian Distribution:
Western Australia, Northern Territory, Queensland.

Western Australia: Gardner, Fitzgerald. Giles. Northern Territory: Darwin & Gulf, Victoria River. Queensland: Burke, North Kennedy, South Kennedy, Port Curtis, Leichhardt, Moreton.

Classification. (GPWG 2001):
Panicoideae: Paniceae

Notes
Native (?). Native to Asia but now occurs throughout the tropics. Flowers Jan.–Aug.