Cenchrus spinifex*

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.
, 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.
), [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South
(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).

[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

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 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.

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

: 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.

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


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