Digitaria bicornis*

Digitaria bicornis* (Lam.) Roem. &
Schult. Syst.Veg.2: 470 (1817).

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

Basionym and/or
Replacement Name:
Lam., Tabl. Encycl. 1: 176 (1791).

Type of Basionym or
Protologue Information
: India:,
P. Sonnerat s.n. (HT: P-LAM; IT: US-2854145n (fragm.))

Recent synonyms:
D. queenslandica.

Key references
(books and floras):
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of

Habit. Annual.
Rhizomes absent. Stolons absent. Culms decumbent, 20–80 cm tall, 2–5 -noded.
Mid-culm internodes glabrous. Mid-culm nodes glabrous. Lateral branches
sparsely branched. Leaf-sheaths glabrous on surface or hairy. Leaf-sheath
auricles absent, or present. Ligule an eciliate membrane, 2 mm long, truncate.
Leaf-blades elliptic, flat, 1–19.5 cm long, 2–10 mm wide. Leaf-blade surface
scaberulous or scabrous, indumented.

Inflorescence digitate, with racemose branches. Racemes 2–4, straight, 5–10 cm
long. Central inflorescence axis 0–1.3 cm long.

Spikelets pedicelled, 2 in the cluster. 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, 2.9–3.5 mm long. Rhachilla internodes brief up to lowest
fertile floret.

Glumes. Lower
glume ovate. Upper glume lanceolate, 2.1–2.8 mm long, membranous, 3 -nerved.
Upper glume surface glabrous or indumented. Florets. Basal sterile
florets 1, barren, without significant palea. Lemma of lower sterile floret 100
% of length of spikelet, membranous, 5–7 -nerved.

Fertile lemma 2.8–3.4
mm long, without keel, 3 -nerved. Lemma apex muticous. Lodicules present.
Anthers 3. Grain 2–2.5 mm long.

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

: Western Australia, Northern Territory, Queensland.

Western Australia: Gardner, Dampier. Northern Territory: Darwin & Gulf, Victoria
River, Barkly Tableland. Queensland:
Burke, Cook, Leichhardt, Mitchell, Moreton, North Kennedy, Port Curtis, South
Kennedy, Wide Bay, Gregory North, Gregory South.

Closely related to D. ciliaris.

In tropical and
subtropical sub-humid woodlands, shrub steppe shrublands, and coastal
grasslands. A species preferring coarse-textured soils in tropical or
subtropical areas. Flowers mostly Feb.-Apr.

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