Common name: Thick Twist Rush
Caustis pentandra R.Br. APNI*
Description: Perennial with short, stout rhizome.
Culms smooth, 45–60 cm long or more, 3–8 mm diam.
Leaf sheaths very dark red-brown to blackish. Inflorescence with 5–12 distant clusters of branches, 20–120 cm long, ultimate branches straight or somewhat spreading. Spikelets 1- or 2-flowered, 10–15 mm long. Glumes 4–6, acute, long-mucronate (lower glumes) to short-mucronate (upper glumes), red-brown to dark grey-brown, puberulous, margins hyaline and ± ciliate, 9–13 mm long. Stamens 5; anthers 5.0–6.0 mm long, excluding appendage 0.5–1.1 mm long. Style 4- or 5-fid; persistent style base 2.5–3.5 mm long, straw-coloured.
Nut narrow-ellipsoid to narrow-ovoid, 4.5–8 mm long, 2.0–2.3 mm diam., punctulate, whitish to straw-coloured.
Distribution and occurrence: Grows in heath and open woodland, on sandstone, usually in seasonally damp habitats; mainly coastal, extending inland to the Blue Mtns.
NSW subdivisions: NC, CC, SC, CT, CWS
Other Australian states: Qld Vic. Tas. W.A. S.A.
Characteristically, the leaf sheaths are wrinkled.
Text by K. L. Wilson
Taxon concept: Flora of NSW 4 (1993)
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.