Australian Tropical Rainforest Plants - Online edition

Cyperus involucratus Rottb.


Weed
Grass
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Scale bar 10mm. © CSIRO
Family

Rottboell, C.F. (1772) Descriptiones Plantarum Rariorum: 22.

Common name

Umbrella plant

Stem

Perennial sedge with short rhizome. Stems tufted, rigid, subterete to trigonous below inflorescence. Usually flowers and fruits when ca. 1-2 m tall.

Leaves

Leaf blades grass-like, 20-30 x 0.4-1.5 cm, margins finely toothed and quite capable of cutting fingers, midrib similarly toothed.

Flowers

Inflorescence terminal, produced on a long peduncle which ends in a series of l12-22 leafy bracts which are much longer than the inflorescences. Inflorescence a panicle of spikes. Spikes up to 2 x 2 cm; spikelets compressed, 5-10 x 1.8-2 mm, 20-40 -flowered; rachilla straight; glumes 1.8-2 mm long. Anthers ca. 1 mm long, filaments ca. 0.25 mm long. Style ca. 1 mm long and then divided into three branches each ca. 1.5 mm long.

Fruit

Nut yellowish brown, ellipsoid, trigonous, apiculate and nearly length of the glume.

Seedlings

Features not available.

Distribution and Ecology

An introduced species with a pantropic distribution, now naturalised in WA, NT, CYP, NEQ, CEQ and southwards in Australia. Altitudinal range in NEQ from near sea level to 520 m. Grows in various types of vegetation including rain forest, but usually found in swampy situations on the edge of waterways.

Synonyms
Cyperus involucratus Poir. [nom.illeg.]Encyclopedie Methodique, Botanique 7: 253 (1806), Type: Cette plante a ete recueillie a Madagasca par M. du Petit-Thouars .. (V.s. in herb. P. T.).
RFK Code
3473
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