Common name
Large Bluegrass

Derivation
Ischaemum L., Sp. Pl. 1: 1049 (1753); Gen. Pl. 5th edn, 469 (1754); from the Greek ischo (to restrain) and haima (blood), as woolly seeds of the type species were reported as being used to stop bleeding.

australe- from the South (Australia).

Published in
Prodr. 205 (1810).

Common synonyms
Ischaemum arundinaceum F.Muell. ex Benth.
Ischaemum villosum R.Br.

Habit
Perennial, tufted. Rhizomes short. Culms erect, 50–150 cm tall, 4–5-noded. Mid-culm nodes glabrous or pubescent or bearded. Lateral branches simple or branched. Leaf-sheaths 10–15 cm long, glabrous on surface. Ligule a fringed membrane, 2–3 mm long. Leaf-blades 10–20 cm long, 3–5 mm wide. Leaf-blade surface glabrous.

Inflorescence
Inflorescence with ramose branches. Rames paired, 3–10 cm long. Rhachis fragile at the nodes, angular, ciliate on margins. Rame internodes oblong, 3–6 mm long, flat and forming a U or V shape with the pedicel in rear view. Rame internode tip transverse, cupiliform.

Spikelets
Spikelets in pairs, one sessile and fertile and the other (companion) spikelet pedicelled. Pedicels oblong, 70–80% of length of internode, ciliate. Companion spikelets developed, male or sterile, asymmetrical, lanceolate, laterally compressed, 6–7 mm long, as long as fertile, separately deciduous. Companion spikelet glumes chartaceous, keeled, winged on keels. Companion spikelet lemmas 2, enclosed by glumes, entire, muticous. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret male, upper fertile, without rhachilla extension, lanceolate, dorsally compressed, 6–7 mm long, falling entire, deciduous from the base or with accessory branch structures. Spikelet callus base truncate, inserted.

Glumes
Glumes dissimilar, firmer than fertile lemma. Lower glume oblong, asymmetrical, 100% of length of spikelet, chartaceous, 2-keeled, keeled laterally, narrowly winged on keel. Lower glume surface flat. Lower glume apex acute. Upper glume lanceolate, chartaceous, 1-keeled, winged on keel, 7-nerved. Upper glume margins ciliolate.

Florets
Basal sterile florets 1, with palea. Lemma of lower sterile floret lanceolate, membranous, 3-nerved, ciliate on margins, acute. Fertile lemma oblong, membranous. Lemma apex dentate, 2-fid, 1-awned. Median (principal) awn from a sinus, curved, 8–10 mm long overall. Anthers 3, 3–5 mm long.

Continental Distribution:
Tropical Asia, Australasia.

Australian Distribution:
Western Australia, Northern Territory, Queensland, New South Wales.

Western Australia: Gardner, Fitzgerald, Dampier. Northern Territory: Darwin & Gulf, Victoria River, Barkly Tableland. Queensland: Cook, North Kennedy, South Kennedy, Port Curtis, Leichhardt, Wide Bay, Darling Downs, Moreton. New South Wales: North Coast, Central Coast.

Classification. (GPWG 2001):
Panicoideae: Andropogoneae

Notes
Native. Coastal districts, usually in wet situations. There are three varieties.

Ischaemum australe var. arundinaceum (F.Muell. ex Benth.) B.K.Simon
Coastal regions of northern Qld, N.T. and northern W.A. in wet situations. Flowers Jan.–Mar. and Aug.–Sept.

Ischaemum australe var. villosum (R.Br.) Benth.
Coastal regions of northern N.S.W., Qld and N.T. in wet situations. Flowers Aug.–July.

Ischaemum australe R.Br. var. australe
Coastal districts from central N.S.W. through to the eastern Kimberley, W.A., in wet situations. Flowers Nov.–July.