Sporobolus coromandelianus (Retz.)
Kunth
|
Common name
Small Dropseed
Derivation
Sporobolus R.Br., Prodr. 169 (1810); from the Greek spora (seed)
and bolos (throwing), alluding to the free seed and (presumably) the
sometimes forcible manner of its release.
coromandelianus- from the Coromandel, that is south-eastern India.
Published in
Rev. Gram. 1: 68 (1829).
Common synonyms
Vilfa commutata Trin.
Vilfa roxburghiana Nees ex Wight
Sporobolus javensis Ohwi
Habit
Annual or ephemeral, tufted. Culms erect or geniculately ascending, 730
cm tall. Lateral branches simple or sparsely branched. Ligule a fringe of hairs,
0.351 mm long. Leaf-blades linear, flat, 211 cm long, 25 mm
wide. Leaf-blade margins glabrous or ciliate, hairy at base.
Inflorescence
Inflorescence compound, a panicle. Panicle open or contracted, ovate, 28
cm long. Primary panicle branches spreading, whorled at most nodes.
Spikelets
Spikelets solitary. Pedicels 0.61.1 mm long. Fertile spikelets 1-flowered,
comprising 1 fertile floret, without rhachilla extension, lanceolate, terete,
11.6 mm long, breaking up at maturity. Spikelets disarticulating below
each fertile floret.
Glumes
Glumes deciduous, dissimilar. Lower glume elliptic or ovate, 0.10.5 mm
long, 1030% length of upper glume, hyaline, 0-nerved. Lower glume
apex obtuse. Upper glume lanceolate or oblong, 11.6 mm long, equalling
adjacent fertile lemma, membranous, grey, 1-nerved. Upper glume lateral nerves
absent. Upper glume surface smooth or asperulous. Upper glume apex acute.
Florets
Fertile lemma oblong or ovate, 11.6 mm long, membranous, grey, 13-nerved.
Lemma surface smooth or scaberulous. Lemma apex obtuse or acute. Palea 2-nerved.
Palea keels approximate. Palea apex entire, obtuse. Anthers 3, 0.20.3
mm long. Grain with free soft pericarp, obovoid, 0.70.9 mm long.
Continental Distribution:
Africa, Temperate Asia, Tropical Asia, Australasia.
Australian Distribution:
Western Australia, Northern Territory, Queensland.
Western Australia: Gardner, Fortescue, Carnarvon. Northern Territory: Darwin & Gulf. Queensland: Cook, Burke, North Kennedy, South Kennedy, Port Curtis, Leichhardt, Darling Downs, Gregory North, Maranoa.
Classification. (GPWG
2001):
Chloridoideae: Cynodonteae
Notes
Introduced; isolated occurrence in subtropical and tropical Australia; New Guinea,
southern Africa, Eastern Asia, and the Pacific region. Mostly collected as a
weed of gardens and roadsides and appears to be spreading; flowers Jan.Dec.
Habit and details (line drawing)
© Simon and Jacobs 1999
plant, inflorescence, spikelet, grain, transverse section of grain, junction
of leaf blade and sheath showing ligule
drawn by M.Saul