Urochloa decumbens* (Stapf) R.D.
Webster. Australian Paniceae (Poac.): 234: (1987).
Classification. (GPWG 2001) : Subfamily Panicoideae. Paniceae.
Basionym and/or
Replacement Name: Brachiaria
decumbens Stapf, Fl. Trop. Afr. 9: 528 (1919).
Type of Basionym or
Protologue Information: ST: Speke & Grant 488, Tanzania: Bukoba
Distr.: Karagwe (K). ST: Dümmer 1070, Uganda: Mengo Distr.: M'pumu, 400
ft (K).
Key references
(books and floras): [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of
Australia (as Brachiaria), [2008] S.W.L.Jacobs, R.D.B.Walley &
D.J.B.Wheeler, Grasses of New South Wales (394).
Illustrations:
[1983] J.C.Tothill & J.B.Hacker, Grasses of Southern Queensland (132
as Brachiaria), [2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses
of New South Wales, 4th edn (394).
Habit.
Perennial. Rhizomes absent or present. Stolons present. Culms decumbent, 50–150
cm tall, wiry. Mid-culm internodes glabrous. Mid-culm nodes glabrous. Ligule a
fringe of hairs. Leaf-blades linear or lanceolate, 5–20 cm long, 7–15 mm wide.
Leaf-blade surface glabrous or indumented.
Inflorescence.
Inflorescence compound, a panicle of racemes. Racemes 2–7, 1–6 cm long, 4–5 mm
wide. Central inflorescence axis 1–8 cm long.
Spikelets.
Spikelets sessile. Fertile spikelets 2-flowered, the lower floret barren
(rarely male), the upper fertile, comprising 1 basal sterile florets,
comprising 1 fertile floret(s), without rachilla extension, elliptic, dorsally
compressed, 4–5 mm long. Rhachilla internodes elongated between glumes.
Glumes. Glumes
dissimilar, thinner than fertile lemma. Lower glume ovate, membranous, without
keels, 7–9 -nerved. Upper glume oblong, 3.9–4.9 mm long, membranous, without
keels, 7 -nerved. Upper glume surface glabrous or indumented. Upper glume apex
muticous. Florets. Basal sterile florets 1, male, with palea. Lemma of
lower sterile floret 100 % of length of spikelet, membranous, 5 -nerved.
Fertile lemma 3.5–4.8
mm long, without keel. Lemma apex mucronate. Palea without keels.
Continental
Distribution: Africa, Tropical Asia, Australasia, and South America.
Australian
Distribution: Western Australia, Northern Territory, Queensland, New South
Wales.
Western Australia:
Gardner, Fitzgerald. Queensland: Cook, Moreton, South Kennedy, Wide Bay.
New South Wales: North Coast.
Notes.
Diagnostic characteristics include the stoloniferous habit, a flat rachis, and
hairy spikelets. It has, in common with U. brizantha, a pronounced
rachilla between the glumes.
Introduced; W.A. and
Qld. In tropical heaths, tropical and subtropical rain forests, tropical and
subtropical wet sclerophyll forests, and tropical and subtropical sub-humid
woodlands. Widely introduced in tropical areas as a forage species. Flowers
Jan.-Aug.
