Digitaria velutina (Forssk.) P.Beauv. |
Derivation
Digitaria Haller, Hist. Stirp. Helv. 2: 244 (1768). From the Latin
digitus (finger), alluding to the radiating inflorescence branches.
velutina- Latin for velvety (significance unclear).
Published in
Ess. Agrostogr. 51 (1812).
Habit
Annual. Stolons absent. Culms decumbent, 2080 cm tall, 25-noded.
Mid-culm internodes glabrous. Mid-culm nodes glabrous. Lateral branches simple
or sparsely branched. Leaf-sheaths glabrous on surface. Leaf-sheath auricles
present. Ligule an eciliate membrane. Leaf-blades linear or lanceolate, flat,
215 cm long, 317 mm wide. Leaf-blade surface smooth, hirsute. Leaf-blade
margins scabrous.
Inflorescence
Inflorescence subdigitate, with racemose branches. Racemes (3)720,
unilateral, 313 cm long. Central inflorescence axis 17 cm long.
Rhachis narrowly winged, angular, glabrous on surface or with scattered hairs,
scabrous on margins. Spikelet packing imbricate or lax, 5080% of their
length apart.
Spikelets
Spikelets appressed, in pairs, all alike. Pedicels 0.30.7 mm long, scabrous.
Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret sterile,
upper fertile, without rhachilla extension, elliptic, dorsally compressed, subacute,
1.52.1 mm long, falling entire. Rhachilla internodes brief up to lowest
fertile floret.
Glumes
Glumes one (the lower absent or obscure) or two, dissimilar, thinner than fertile
lemma. Lower glume ovate, 00.24 mm long, 10% of length of spikelet.
Upper glume lanceolate, dorsally convex in profile, 1.21.6 mm long, 6580%
of length of spikelet, membranous, 3-nerved. Upper glume surface pubescent,
hairy between nerves. Upper glume apex acute.
Florets
Basal sterile floret 1, without significant palea. Lemma of lower sterile floret
elliptic, 1.62 mm long, 100% of length of spikelet, membranous, 7-nerved,
with equidistant nerves, with nerves free at apex, puberulous or pubescent,
hairy between nerves, eciliate on margins or ciliate on margins, acute. Fertile
lemma elliptic, 1.52.1 mm long, cartilaginous, much thinner on margins,
grey or dark brown, 3-nerved. Lemma surface striate. Lemma margins flat, covering
most of palea, ciliate. Lemma apex muticous. Palea cartilaginous.
Continental Distribution:
Africa, Temperate Asia, Australasia, South America.
Australian Distribution:
New South Wales: Central Coast.
Classification. (GPWG
2001):
Panicoideae: Paniceae
Notes
Introduced. Flowers Jan.May.
Spikelet front and back (line drawing)
© Wheeler et al. 1990