Urochloa ramosa*

Urochloa ramosa* (L.) Nguyen. Fl.
Trop. Afr.
9: 542 (1919).

Classification. (GPWG 2001) : Subfamily
Panicoideae. Paniceae.

Basionym and/or
Replacement Name:
 Panicum ramosum
L., Mant. Pl. 1: 29–30 (1767).

Type of Basionym or
Protologue Information
: India:,
Anon. (LT: LINN-80.44).

Recent synonyms:
Brachiaria ramosa.

Key references
(books and floras):
[1952] C.A.Gardner, Flora of Western
Australia
1 Gramineae (235 as Brachiaria),
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia
(as Brachiaria).

Habit. Annual.
Rhizomes absent. Stolons absent. Culms 10–70 cm tall. Mid-culm internodes
glabrous. Mid-culm nodes pubescent. Ligule a fringe of hairs. Leaf-blades 2–25
cm long, 4–14 mm wide. Leaf-blade surface glabrous.

Inflorescence.
Inflorescence compound, a panicle of racemes. Racemes 3–15, 1–8 cm long, 2–4 mm
wide. Central inflorescence axis 3–13 cm long.

Spikelets.
Spikelets pedicelled. 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, 2.4–3.5 mm long. Rhachilla internodes brief up to lowest fertile
floret.

Glumes. Glumes
dissimilar, thinner than fertile lemma. Lower glume ovate, membranous, without
keels, 3–7 -nerved. Upper glume ovate, 2.5–3.4 mm long, membranous, without
keels, 5–9 -nerved. Upper glume surface glabrous or indumented. Upper glume
apex mucronate. Florets. Basal sterile florets 1, barren, with palea.
Lemma of lower sterile floret 100 % of length of spikelet, membranous or
coriaceous (rarely), 5 -nerved. Fertile florets female.

Fertile lemma 2–3.3 mm
long, without keel. Lemma apex mucronate. Palea without keels.

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

Australian
Distribution
: Western Australia, Northern Territory, Queensland, Christmas Is.

Western
Australia
: Gardner.
Northern Territory:
Darwin & Gulf. Queensland:
Cook, North Kennedy, South Kennedy, Port Curtis, Warrego.

Notes.
Morphologically similar to U. pubigera and they may intergrade in areas
of sympatry, however, Australian specimens are distinct. Diagnostic features of
U. ramosa include a shorter spikelet and a less apiculate apex on the
upper glume and lower lemma.

Introduced. A native
of Africa and Asia. In tropical and
subtropical rain forests and tropical and subtropical sub-humid woodlands. In Australia it
occasionally occurs as a weed in cultivated areas. Flowers Feb.-July.

AVH 2011

  

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith