Australian Tropical Rainforest Plants - Online edition

Juncus usitatus L.A.S.Johnson


Grass
Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
Inflorescence. © Australian Plant Image Index (APII). Photographer: M. Fagg.
10th leaf stage. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
Scale bar 10mm. © CSIRO
Family

Johnson, L.A.S. (1961) Contributions from the New South Wales National Herbarium 3(3): 241. Type: Queensland, Cheltenham, L.A.S. Johnson 23.11.1952 (NSW 20734). ISOTYPES in K (distributed as J.polyanthemos Buchen.) and CHR.

Common name

Soft Rush; Rush

Stem

Sometimes exceeds 1 m in height but usually flowers and fruits when smaller.

Leaves

'Leaves' about 1-1.5 m long, cylindrical, terete, about 1.5-3 mm diam., inside filled with white pith. Base of leaf encased in sheathing bracts about 40-120 mm long. 'Leaves' produced in a straight line along a rhizome. True leaves are scale-like and inconspicuous.

Flowers

Inflorescence glabrous arising from within a 'leaf', one inflorescence per 'leaf'. Each flower subtended by 2-3 bracts. Perianth in two whorls. each consisting of three papery tepals about 1.3-2 mm long. Ovules numerous. Stigmas three, each curled like a corkscrew.

Fruit

Fruits 3-sided, about 2 mm long, perianth persistent at the base. Seeds numerous, golden brown, minute, longitudinally ribbed.

Seedlings

First true leaves are scale-like, sessile and lack or contain little chlorophyll, apex mucronate. At the tenth leaf stage: stems are terete and resemble leaves as they contain chlorophyll but the true leaves are scale-like and inconspicuous. Seed germination time 50 to 72 days.

Distribution and Ecology

Occurs in NEQ, CEQ and southwards as far as Victoria. Altitudinal range in NEQ from 600-1200 m. Usually grows in swampy or wet areas but also found in moist areas along roads and in disturbed areas in upland and mountain rain forest. Also occurs in New Caledonia and New Zealand.

RFK Code
3425
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