Common name: Umbrella Sedge
Cyperus eragrostis Lam. APNI*
Description: Tufted perennial, with very short rhizome.
Culms trigonous, smooth, 25–90 cm high, 2–4 mm diam.
Leaves slightly septate-nodulose, as long as culms or shorter, 4–8 mm wide. Inflorescence simple to decompound with up to 12 primary branches to 12 cm long; digitate clusters 10–50 mm diam.; involucral bracts leaf-like, 5–9 exceeding inflorescence. Spikelets flattened, numerous per cluster, to 30-flowered, 5–15 mm long, c. 3 mm wide; rachilla not winged, persistent. Glumes with 3-nerved midrib, 2–2.5 mm long, surface conspicuously isodiametric-reticulate, greenish to white or straw-coloured, tinged yellowish or red-brown. Stamen 1. Style 3-fid.
Nut triquetrous, obovoid, about half as long as glume, 1–1.4 mm long, c. 0.5 mm diam., dark brown to greyish.
Distribution and occurrence: Weed of rice crops and ephemerally wet, open, disturbed situations; widespread. Native of N & S Amer.
NSW subdivisions: *NC, *CC, *SC, *NT, *CT, *ST, *NWS, *CWS, *SWS, *NWP, *SWP, *SFWP, *LHI
Other Australian states: *Qld *Vic. *Tas. *W.A. *S.A.
This species has extended its range and frequency considerably over the past 30 years.
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.