The New Zealand Plant Conservation Network

Species

Eleocharis pusilla

Etymology

Eleocharis: charm of the swamp
pusilla: Small

Common Name(s)

none known

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Data Deficient
2004 - Not Threatened

Qualifiers

2012 - SO
2009 - SO

Authority

Eleocharis pusilla R.Br.

Family

Cyperaceae

Flora Category

Vascular - Native

NVS Species Code

ELEPUS

Structural Class

Sedges

Synonyms

None - though New Zealand plants have at times been referred to the northern hemisphere Eleocharis acicularis (L.) Roem. et Schult.

Distribution

Indigenous. In New Zealand known from North and South Islands - often ucnommon over large parts of its range, and showing a decided preference for clean waterways free from pollution. Present in Australia.

Habitat

Usually found on the margins of and submerged within lakes, tarns and slow flowing rivers and streams. When submerged it often grows amongst drifts of quillworts (Isoetes spp.) and is rarely fertile. In emergent situations it is is easily overlooked because it has inconspicuous flowers and can be mistaken for a small tuft of grass.

Features

Emergent or aquatic diminutive, sedge forming bright green (when exposed) or dark green to brown-green tufts. Rhizomes 1-3 mm diameter (usually very slender), pale brown. Culms densely tufted, 10-120 mm long, setaceous, < 0.5 mm diameter, bright green (when exposed), dark green to brown green with yellowish transverse bars when submerged; sheaths membranous, more or less hyaline, red-veined, upper most sheaths colourless and inflated below the oblique orifice. Spikelet 2.5-3.0 x c.1 mm, (1-)5-flowered, ovate, sharply acute. Glumes 1.5-2.0 mm long, ovate, obtuse. Hypogynous bristles mostly absent, rarely 2-3 present. Stamens 3, Style 3-fid. Nut c. 1.0 x 0.5 mm, narrowly obovoid, obscurely trigonous, almost white, each face with 3-4 thick, vertical ribs joined by fine transverse bars; the persistent style very small, much constricted at the base.

Similar Taxa

Most likely to be confused with E. gracilis R.Br. from which it differs by the smaller spikelets (up to 3 mm long) and by the nut which has prominent vertical ribs and fine transverse bars. The culms of this species are often bright green, and distinctly tufted so as to resemble a small grass. In submerged plants the culms often have an obvious yellow transverse patterning on the otherwise dark green to bronw-green coloured culms.

Flowering

September - February

Fruiting

November - April

Propagation Technique

Can be tricky to establish. Does best as a submerged aquarium plant where it can be very attractive. Prefers semi-shade and regular immersion in water.

Threats

Not Threatened - but not very common in the northern part of its range where it is clear, based on herbarium evidence that it has undergone a large decline. Still abundant in the deeper, cleaner and less polluted lake systems of the North Island. Common in the South Island.

Chromosome No.

2n = 30

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Bristly nuts are dispersed by water and possibly wind and attachment (Thorsen et al., 2009).

This page last updated on 12 Sep 2014