Australian Tropical Rainforest Plants - Online edition

Oplismenus hirtellus (L.) P.Beauv.


Grass
Click/tap on images to enlarge
Flowers. © G. Sankowsky
Flowers. © G. Sankowsky
Leaves. © G. Sankowsky
Leaves. © G. Sankowsky
Herbarium specimen. © CSIRO
Herbarium specimen. © CSIRO
Family

Palisot de Beauvois, A.M.F.J. (1812) Essai d'une Nouvelle Agrostog 1: 54.

Stem

Weak trailing and creeping perennial 15-40 cm high, culm to 1 m long, rooting at lower nodes, nodes hairy.

Leaves

Leaf blades flat or lower margins wavy, 1-15 x 0.3-1.2 cm; leaf sheath margin densely hairy. Leaf blade glabrous or hairy. Ligule a fringed, ciliate membrane to 1.1 mm long.

Flowers

Inflorescence spike-like, 3-10 cm long, with 4-10 lateral racemes; racemes 3-25 mm long, diminishing upwards, bearing 1-8 spikelets. Spikelets 2-3 mm long, glabrous or sparsely hairy. Glumes subequal, with stiff, straight, or sometimes kinked, smooth, viscid awns; lower glume 3-veined, with awn 4-13 mm long; upper glume broader than lower, 5-7-veined, with awn 0.5-1 mm long. Lemma 2-3 mm long, acute to aristate.

Fruit

Fruits about 4 mm long, enclosed in sepals or bracts at the base. Caryopsis with a pointed apex, testa smooth and glossy.

Seedlings

Features not available.

Distribution and Ecology

Occurs in WA, NT, CYP, NEQ, CEQ and southwards to Victoria. Altitudinal range from near sea level to 1005 m. Grows in shady and moist conditions in rainforest, eucalypt forest, acacia forest, vineforest and hoop pine woodland. Also from the Philippines, Malesia, East Timor, Fiji and Norfolk Island.

Natural History & Notes

In Queensland O. hirtellus is not recognised, and is split into two taxa: Oplismenus aemulus (leaf blade length/width ratio less than 7) and Oplismenus imbecilis (leaf blade length/width ratio greater than 10).

Description adapted from Flora of Australia.

Synonyms
Panicum hirtellum L., Systema Naturae Edn. 10 2: 870(1759). Oplismenus imbecillis (R.Br.) Roem. & Schult., Systema Vegetabilium Edn. 16 2: 487(1817). Oplismenus hirtellus subsp. imbecillis (R.Br.) U.Scholz, Phanerogamarum Monographiae : 127(1981). Orthopogon imbecillis R.Br., Prodromus Florae Novae Hollandiae : 194(1810).  Oplismenus aemulus (R.Br.) Roem. & Schult., Systema Vegetabilium Edn. 16, 2: 487 (1817).  Orthopogon aemulus R.Br., Prodromus Florae Novae Hollandiae : 194(1810).
RFK Code
4083
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