Themeda arguens

Themeda arguens (L.) Hack. DC.
Monog. Phan .
6: 657 (1889).

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

Basionym and/or
Replacement Name:
 Stipa arguens
L., Sp. Pl. (ed. 2) 117 (1762).

Type of Basionym or
Protologue Information
: India: Coll?.

Recent synonyms:
T. frondosa.

Key references
(books and floras):
[1810]. R.Brown, Prodromus (200 as Anthistiria
frondosa
), [1878] G.Bentham, Flora Australiensis 7 (542 as Anthistiria
frondosa
), [1952] C.A.Gardner, Flora of Western Australia 1 Gramineae
(342), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia.

Habit. Annual.
Culms erect or geniculately ascending, 20–300 cm tall. Leaves mostly basal.
Ligule an eciliate membrane, 1 mm long. Leaf-blades flat or conduplicate, 5–30
cm long, 4–7 mm wide.

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

Spikelets.
Spikelets sessile, 1 in the cluster. Companion spikelets pedicelled, 2 in the
cluster. Basal sterile spikelets represented by a single scale, 4 in number.
Companion spikelets developed, comprising 2 subequal glumes without lemmas,
6–10 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, 8–11 mm long.

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

Fertile lemma 3 mm
long, without keel, 1 -nerved. Lemma apex entire, awned, 1 -awned. Median
(principal) awn apical, 50–90 mm long overall, with a twisted column. Palea
absent.

Continental
Distribution
: Tropical Asia, Australasia, Pacific, and South America.

Australian
Distribution
: Western Australia, Northern Territory, Queensland.

Western Australia:
Gardner. Northern Territory: Darwin & Gulf. Queensland:
Burke, Cook, North Kennedy.

Notes. A fairly
widespread tropical species from northern regions of Australia and extending
through SE Asia to the Andaman Is.. Flowers Feb.--Sept.

 

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