Themeda quadrivalvis*

Themeda quadrivalvis* (L.) Kuntze. Rev.
Gen. Pl.
2: 794 (1891).

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

Basionym and/or
Replacement Name:
L., Syst. Veg. (ed. 13) 758 (1774).

Type of Basionym or
Protologue Information
: LT: (LINN-1211.5). LT designated by Cope in
Cafferty et al., Taxon 49(2): 246 (2000).

Key references
(books and floras):
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of
, [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses
of New South Wales

[2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South
, 4th edn (384).

Habit. Annual.
Basal leaf sheaths present. Culms erect or geniculately ascending, 30–200 cm
tall, 4–6 mm diam., 5–7 -noded. Mid-culm nodes glabrous. Ligule an eciliate
membrane, 1–2.5 mm long. Leaf-blades conduplicate, 7–60 cm long, 1–6 mm wide.
Leaf-blade surface smooth or scaberulous, glabrous or indumented.

Inflorescence compound, of pedicelled spikelet clusters. Rhachis fragile at the

Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 1 in the
cluster. Basal sterile spikelets well-developed, 4 in number. Companion
spikelets developed, comprising 2 subequal glumes without lemmas, 4–6 mm long.
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, terete, 4.5–5.5 mm long.

Glumes. Glumes
dissimilar, firmer than fertile lemma. Lower glume oblong, coriaceous, much
thinner above, without keels, 7–9 -nerved. Lower glume surface indumented.
Upper glume oblong, 3 -nerved. Florets. Basal sterile florets 1, barren,
without significant palea. Lemma of lower sterile floret hyaline, 1 -nerved.

Fertile lemma without
keel, 1 -nerved. Lemma apex entire, awned, 1 -awned. Median (principal) awn
apical, 10–45 mm long overall, with a twisted column. Palea absent.

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

: Western Australia, Northern Territory, Queensland, New South

Western Australia:
Gardner, Hall, Dampier. Northern Territory: Darwin & Gulf. Queensland:
Burnett, Cook, Leichhardt, Moreton, North Kennedy, Port Curtis, South Kennedy,
Wide Bay. New South Wales: North Coast.

Notes. From
India and Burma, now fairly widespread in areas to the east and west of the
Indian subcontinent. Naturalised in Australia mostly in subtropical and
tropical coastal Qld with a few records from N.T. and W.A. Flowers Feb.--Oct.

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