Cyperus tenellus L.f.
Small tufted annual, 2-10 cm high. Stems numerous, filiform. Leaves 1-2 basal, much > stems, setaceous; sheaths hyaline, mostly colourless but occasionally red-tinged at base. Inflorescence a solitary cluster of (1)-2-(5) comparatively large, digitate, very compressed spikelets varying from whitish-green to greenish-brown; lower subtending bract setaceous, < or > inflorescence, appearing as a continuation of the stem, occasionally a second setaceous bract or an upper spikelet with a short glume-like bract. Spikelets ± 3-8 × 2-3 mm, oblong to ovate-lanceolate. Glumes many, densely imbricate, ± 2 mm long, obtuse, distinctly nerved, margins occasionally brown-splotched, keel green, later brown, tip slightly spreading. Stamens 1 or 2. Style-branches 3. Nut slightly > ½ length of glume, ellipsoid, acutely triquetrous.
N. North Auckland; Auckland - Auckland City, Waikato, Hauraki Plains. S. Nelson - West Wanganui Inlet. Lake and stream margins, swampy roadsides. (S. Africa, Australia)
First record: Hooker 1867: 745.
First collections: Auckland, T. Kirk, 12 Oct. 1863 (WELT 21277, 21281); Between Newton and Auckland, T. Kirk, Oct. 1863 (WELT 21280).
In the small size, filiform leaves and stems, and usually single involucral bract, C. tenellus resembles spp. of Scirpus sect. Isolepis, but is distinguished by the flattened spikelets; the record of C. tenellus as abundant in lowlands of Canterbury and on Banks Peninsula (Armstrong T.N.Z.I. 12, 1880, 344, 353) might well have referred to a small sp. of Scirpus but no specimens have been seen.
C. tenellus grows in a range of habitats - in pasture, cultivated land, waste places, gardens, margins of lakes, swamps, streams, drain banks, crevices of gutter channels, pathways, and on railway ballast - and is at times a nuisance because the numerous small plants form dense mats or colonies.
