Setaria (pigeon grasses) have flowers surrounded and enclosed by rough bristles. There are five native and seven introduced species in Western Australia. S. gracilis (slender pigeon grass) is a rhizomatous tufted perennial to 1.2m tall. The inflorescence is a green, cylindrical panicle, to 10cm long, produced in summer. A locally common roadside weed from Mogumber to Albany. Native to America. S. italica (Italian millet) is a tufted annual, to 1.5m tall. The inflorescence is a cylindrical, green, very dense often lumpy panicle, 3-18cm long, produced in summer. It is cultivated for seed, and found on disturbed sites from Perth to Goomalling and Katanning. It is of hybrid origin.
Setaria
italica , PH
S. palmifolia is a robust, tufted perennial, to 1.5m tall with palm-like leaves to 1m long. The inflorescence is an erect or nodding, loose panicle, with long flexuose-straight branches. Flowers in summer. A garden plant, now scattered in disturbed swamps and creeks from Perth to Busselton. Native to the Old World tropics.
S.
palmifolia
, RR
S.
pumila
(pale pigeon grass) is a loose or densely-tufted annual to
1.3m tall. The inflorescence is a long, exserted,
spike-like, dense panicle, produced in summer. Found in
disturbed sites from Perth to Harvey. Native to warm and
temperate regions of the Northern Hemisphere.
S. sphacelata (South African pigeon grass) is a compact to tufted
perennial to 2m tall. The inflorescence is an erect, green,
dense, spike-like panicle, produced in summer. It is a
pasture grass naturalised around Kununurra on verges and
from Perth to Kojonup. Native to tropical Africa.
S.
verticillata
(whorled pigeon grass) is a loosely-tufted annual to 1m
tall. The inflorescence is a dense, spike-like, erect or
nodding, cylindrical panicle,
2-30cm long, flowering in summer. A common and widespread
weed of disturbed land, riverine edges and shrublands from
the Kimberley and Pilbara south to Three Springs, with one
record from Albany. Native to temperate and tropical regions
of the Old World. S. viridis (green pigeon grass) is a loosely-tufted annual to 1m tall.
The inflorescence is a dense, spike-like, erect or nodding,
cylindrical panicle, 2-30cm long, produced in summer.
Naturalised around Kununurra. Native to temperate regions of
the Old World. (Very similar to, and probably a form of,
S.
verticillata.)
S.
pumila
, GK
There are
10 Sorghum
species
in Western Australia, three of which are
introduced.
S. x
almum
(Columbus grass) is a perennial with a strong rhizome,
apparently a hybrid derivative of S.
bicolor and S.
halepense.
It is cultivated for seed and forage and flowers in summer.
A roadside, creek and wetland weed in the Kimberley.
S. bicolor (grain or cultivated sorghum) is a large tufted annual to
2.5m tall. The inflorescence is a pyramidal panicle, to 40cm
by 25cm wide, produced in summer. It is found on verges and
disturbed sites around Kununurra. Native to
Africa.
Sorghum
x
almum
, GK
S. halepense (Johnson grass) is a rhizomatous perennial to 1.5m tall. The inflorescence is a purplish-brown, pyramidal panicle, to 20cm by 12cm wide, produced in summer. Found on disturbed, usually swampy, sites from Perth to Albany and also at Kununurra. Native to the Mediterranean. S. sudanense (Sudan grass) closely resembles S. halepense but is a tufted annual. Theflowers are produced in spring and summer. Found in disturbed swampy sites from Perth to Albany. Native to the Sudan.
Spinifex sericeus is a stout, creeping, stoloniferous perennial to 20cm tall by 4m wide, with silvery-grey leaves and large, ball-shaped female flower-heads. Flowers in spring. It has been planted for beach stabilisation and is naturalised at Perth, Rottnest, Bunbury and Denmark. A native of eastern Australia. In the same locations, the native S. hirsutus can also be found. It has broader leaves and looks more robust.
S. halepense , PH
Sporobolus has nine species in Western Australia, two of them naturalised. S. indicus var. capensis (was S. africanus) (Paramatta grass, rats' tails) is a tufted perennial with basal leaves, to 50cm tall. The inflorescence is dark green, flat, spike-like, to 20cm long, produced in spring and summer. A lawn, road verge, pasture and disturbed site weed from higher rainfall areas, Perth to Albany. Native to Africa. S. ? pyramidalis is a tufted perennial with basal leaves to 60cm tall. The inflorescence is a much-branched, narrowly oblong to linear, pyramidal panicle, to 30cm long by 2cm wide. Flowers in winter. A weed of lawns and disturbed ground in the Kimberley. Native to Africa.
Sporobolus
indicus
var. capensis
, RR
