Australian Tropical Rainforest Plants - Online edition

Cymbopogon refractus (R.Br.) A.Camus


Grass
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Herbarium specimen. © DERM
Flowers. © Australian Plant Image Index (APII). Photographer: M. Fagg.
Family

Camus, A.A. (1921) Revue de Botanique Appliquée 1: 279.

Common name

Barbed Wire Grass

Stem

Tufted perennial. Culms erect, 50-100 cm long and 2-3 -noded. Culm-nodes glabrous.

Leaves

Ligule a ciliate membrane 1-2 mm long. Leaf-blades flat or revolute, 10-25 cm long and 1.25-2 mm wide; aromatic; scabrous, rough abaxially, margins scabrous, apex attenuate. Upper part of the leaf sheath situated away from the culm. Dried leaves curly and pinkish brown.

Flowers

Synflorescence compound, linear, lax. Inflorescence composed of terminal and axillary racemes subtended by a spatheole. Spatheole 2-2.5 cm long. Peduncle 0.5-1 cm long. Racemes 2, paired, deflexed, 1-2 cm long bearing 2-6 fertile spikelets on each. Rhachis fragile at the nodes, semiterete and ciliate on the margins, hairs ca. 1.75 mm long, rhachis internodes linear, ca. 3 mm long; . rhachis internode tip transverse, cupuliform. Raceme-bases flattened, subequal, 1-5 mm long. Spikelets in pairs. Fertile spikelets sessile. Companion sterile spikelets pedicelled. Pedicels linear, semiterete, ca. 3 mm long, ciliate with ca. 1.75 mm long hairs. Basal sterile spikelets represented by a single scale; 2 in lower raceme, sessile and pedicelled. Basal sterile spikelet pedicels free, linear. Basal sterile spikelets equalling fertile spikelet. Companion sterile spikelets well-developed, comprising 2 unequal glumes without lemmas, lanceolate, 5 mm long. Companion sterile spikelet glumes coriaceous, 11 -veined, acuminate, pungent. Spikelets lanceolate, dorsally compressed, acuminate, 4.5-6 mm long, falling entire, deciduous with accessory branch structures. Spikelet callus pilose with the base obtuse. Glumes dissimilar, exceeding apex of florets, firmer than fertile lemma. Lower glume lanceolate, same length than spikelet, chartaceous, 2-keeled, wingless. Lower glume with intercarinal veins distinct, 4-5 in number. Lower glume surface flat. Upper glume lanceolate, chartaceous, keeled, 7 -veined. Upper glume margins ciliolate, apex acute, or acuminate. Lemma of lower sterile floret lanceolate, 4.5 mm long, hyaline, without lateral veins, ciliolate on margins. Fertile lemma lanceolate, ca. 3.5 mm long, hyaline, without a keel. Lemma margins ciliolate, apex entire, or dentate, 2 -fid, mucronate, or awned. Principal lemma awn from a sinus, straight, 1-12 mm long overall, without a column. Palea absent or minute.

Fruit

Caryopsis with adherent pericarp, ellipsoid, 2.5-4.5 mm long.

Seedlings

Features not available.

Distribution and Ecology

Occurs in the NT, CYP, NEQ, CEQ and southwards to Victoria. Altitudinal range from near sea level to 920 m. Grows in clearings in rainforest, monsoon forest, melaleuca forest, open Eucalypt forest, vine thicket, various types of woodland, Leucopogon scrub and wooded grassland. naturalised in Tahiti, Hawaii, Fiji and New Caledonia.

Synonyms
Andropogon refractus R.Br., Prodromus Florae Novae Hollandiae : 202(1810), Type: Port Jackson R. Brown [6177] (BM, holo; E, K, P).
RFK Code
4255
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