Cenchrus spinifex* Cav. Icon.
5: 38, t. 461 (1799).
Classification. (GPWG 2001) : Subfamily
Panicoideae. Paniceae.
Type of Basionym or
Protologue Information: Hab. in Regne chilensi iuxta fundum Longavi, neonon
prope Montavideol,.
Recent synonyms:
Cenchrus incertus M. A. Curt., Boston J.Nat. Hist.1: 135 (1837); C.
pauciflorus, C. tribuloides auct.
Key references
(books and floras): [1952] C.A.Gardner, Flora of Western Australia 1
Gramineae (286 as C. incertus, 288 as C. pauciflorus),
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia (as C.
incertus), [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South
Australia (434 as C. incertus), [2008] S.W.L.Jacobs, R.D.B.Walley
& D.J.B.Wheeler, Grasses of New South Wales (as C. incertus).
Illustrations:
[1952] C.A.Gardner, Flora of Western Australia 1 Gramineae (287,
Pl.83 as C. incertus, 289, Pl.84 as C. pauciflorus), [2006]
J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (434, fig. 364), [2008] S.W.L.Jacobs,
R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th edn
(180 as C. incertus).
Habit. Annual.
Rhizomes absent. Stolons absent. Culms erect or geniculately ascending, 5–80 cm
tall. Ligule a fringe of hairs, 1–1.5 mm long. Leaf-blades 2–18 cm long, 2–6 mm
wide.
Inflorescence.
Inflorescence solid, of only a few spikelets (spicate). Panicle linear, 2–8.5
cm long, 0.8–2 cm wide. Racemes 2–8.5 cm long, 0.8–2 mm wide.
Spikelets.
Spikelets sessile, 2–4 in the cluster. Involucre composed of bristles, connate
into a cup below (cleft on 2 sides). 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, ovate,
dorsally compressed, 3.5–5.8 mm long.
Glumes. Glumes
thinner than fertile lemma. Lower glume ovate, membranous, without keels, 1
-nerved. Upper glume ovate, 2.8–5 mm long, membranous, without keels, 5–7
-nerved. Florets. Basal sterile florets 1, barren, with palea. Lemma of
lower sterile floret 100 % of length of spikelet, membranous, 5–7 -nerved.
Fertile lemma 3.4–5.8
mm long, without keel, 3 -nerved. Anthers 3. Grain 1.3–3 mm long.
Continental
Distribution: Europe, Africa, Temperate Asia, Tropical Asia, Australasia,
North America, and South America.
Australian
Distribution: Western Australia, South Australia, Queensland, New South
Wales, Victoria.
Western Australia:
Drummond. South Australia: Eyre Peninsula, Northern Lofty, Murray. Queensland:
Burnett, Darling Downs, Moreton. New South Wales: North Coast, Central
Coast, South Coast, North-Western Slopes, Central-Western Slopes, North-Western
Plains, South-Western Plains. Victoria: Riverina.
Notes.
Introduced. In temperate rain forests, tropical and subtropical wet sclerophyll
forests, dry sclerophyll forests, Brigalow forests, tropical and subtropical
sub-humid woodlands, temperate sub-humid woodlands, semi-arid shrub woodlands,
arid and semi-arid low woodlands, and tropical sub-humid grasslands. Flowers
Dec.-May.
