Species

Isolepis lenticularis

Etymology

Isolepis: From the Greek isos (equal) and lepis (scale)

Common Name(s)

None Known

Current Conservation Status

2012 - Threatened - Nationally Vulnerable

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 - Threatened - Nationally Vulnerable
2004 - Gradual Decline

Qualifiers

2012 - SO
2009 - DP, SO

Authority

Isolepis lenticularis R.Br.

Family

Cyperaceae

Flora Category

Vascular - Native

Structural Class

Sedges

Synonyms

Scirpus fluitans L., Eleogiton fluitans (L.) Link, Isolepis fluitans (L.) R.Br.; Isolepis fluitans (L.) R.Br. var. fluitans - all refer to a Northern Hemisphere plant not in New Zealand

Distribution

Indigenous. Cosmopolitan. In New Zealand known from North and South Islands.

Habitat

Slow to fast flowing streams, ponds, tarns or lakes, often found floating amongst other plants such as Baumea arthrophylla (Nees) Boeck., Isolepis crassiuscula Hook.f., or by itself. In alpine habitats often the only aquatic macrophyte present, and in these habitats it can be found in very fast flowing, well aerated water. Usually forming diffuse, submerged to semi-emergent patches but also rarely found as an emergent in ephemeral wetlands, in which case it forms dense mats.

Features

Annual or short-lived perennial, forming diffuse to dense floating or terrestrial mats. Roots minute, rhizomes thread-like, green above ground. Culms 10-47(or more) mm , 0.2-1.1 mm diam., with one or more internodes, peduncle 10-190 mm, 0.2-0.9 mm diam. Leaf sheath 3-25 x 0.3-1.7 mm, green or brown, lamina 2-80 x 0.2-1.1 mm. Inflorescence terminal, not proliferating; bract 2-12 x 0.3 - 1.3 mm. Spikelet 1, 2.4-9.4 x 0.7-2.7 mm, with 4-28 glumes. Glumes 1.5-3.4 x 0.5-1.3 mm, acute to obtuse, green or with brown patches, midrib green extending beyond glume to a fine mucro <0.1 mm long. Style bifid. Stamens 2, anthers 0.4-1.5 mm, crested. Nutlets 0.9-1.8 x 0.5-1.2 mm, brown, minutely reticulate.

Similar Taxa

Most commonly confused with I. crassiuscula which differs from I. lenticularis in having 3 stamens, and much wider spikelets. The culms in this species are usually yellow-green to glaucous, not grass-green as in I. lenticularis.

Flowering

December - March

Fruiting

January - May

Propagation Technique

Difficult and should not be removed from the wild.

Threats

Threatened throughout New Zealand by the spread of wetland weeds, eutrophication, and wetland drainage. In the North Island virtually confined to the Central Volcanic Plateau, though it was once widespread from Northland to the Manawatu. In the South Island now virtually restricted to the West Coast where it is still locally common.

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

Where To Buy

Not commercially available.

Attribution

Fact Sheet prepared by P.J. de Lange (14 April 2006). Description adapted from Moore and Edgar (1970)

References and further reading

Ito, Y.; Viljoen, J-A.; Tanaka, N.; Yano, O.; Muasya, A.M. 2015: Phylogeny of Isolepis (Cyperaceae) revisited: non-monophyletic nature of I. fluitans sensu lato and resurrection of I. lenticularis. Plant Systematics and Evolution 301:1-8.

Johnson, A. T. and Smith, H. A (1986). Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd: Buckenhill, UK.

Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.

 

Isolepis habra

This page last updated on 10 Feb 2017