The New Zealand Plant Conservation Network

Species

Poa polyphylla

Etymology

Poa: meadow grass

Common Name(s)

Kermadec Islands Poa

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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 - At Risk - Naturally Uncommon
2004 - Range Restricted

Qualifiers

2012 - IE, RR

Authority

Poa polyphylla Hack.

Family

Poaceae

Flora Category

Vascular - Native

Structural Class

Grasses

Synonyms

Poa anceps subsp. polyphylla (Hack.) Edgar

Distribution

Endemic. New Zealand: Raoul and Macauley Islands, Kermadec Islands group

Habitat

On coastal cliffs, near seepages or in exposed ground near petrel burrows, also on roadside banks on Raoul Island.

Features

Loosely tufted, widely creeping, perennial with trailing culms up to 0.8 m; culms equalled or overtopped by numerous dull green, leaves and stems drooping from thick stolons, rooting at nodes below tufts; branching extravaginal, with up to three, short, glabrous, obtuse, bract-like sheaths at base; leaf-blades persistent. Leaf-sheath light green to light brown, coriaceous, folded and strongly keeled, lateral ribs conspicuous, smooth, glabrous. Ligule 0.5 mm, a truncate usually long-ciliate rim, scabrid abaxially. Leaf-blade 65.0-200.0 × 1.0-2.5 mm, coriaceous, folded to flat, upper surface densely minutely papillose or glabrous, smooth between inconspicuous ribs, minutely pubescent-scabrid just above ligule, undersides with prominent, thickened midrib, and numerous, distinct lateral ribs, smooth apart from prickle-teeth near tip; margins sparsely ciliate near ligule and scabrid near tip, otherwise thickened, tip acuminate or abruptly acute, pungent, scabrid. Culm 70-700 mm, often not far exserted beyond uppermost leaf-sheath, internodes glabrous. Panicle 35-150 mm, contracted, ± oblong, with few, stiff, erect branches, or slightly more open with finer branches; rachis and primary branches often smooth, secondary branchlets finely, sharply, densely or sparsely scabrid or smooth, often spikelet-bearing ± throughout. Spikelets numerous, 4.5-5.5 mm, 3-4-flowered, light green. Glumes subequal, narrow- to elliptic-lanceolate, acute to subobtuse, occasionally smooth throughout, or upper 2/3 scabrid; lower glume 2.0-3.5 mm, 1-3-nerved, upper glume 2.5-5.0 mm, 3-nerved. Lemma 3.0-4.5 mm, 5-nerved, elliptic-oblong, acute or occasionally apiculate, internerves glabrous, midnerve with short crinkled hairs on lower ½ and near base of outer lateral nerves; margins minutely scabrid. Palea 2.5-4.0 mm, keels finely scabrid, interkeel and flanks smooth or minutely scabrid. Callus with thick tuft of soft crinkled hairs. Rachilla c.0.5 mm, smooth or minutely, sparsely scabrid; prolongation c. twice as long. Lodicules c.0.5 mm, occasionally hair-tipped. Anthers c.1.5 mm. Seed 1.5 × 0.5 mm.

Similar Taxa

Allied to Poa anceps G.Forst. from which it differs by its geographic isolation on the Kermadec Islands; smaller overall size; glabrous leaf-sheath,; densely minutely papillose or glabrous adaxial leaf surface; smaller spikelets size range (4.5-5.5 cf. 3.0-7.5 mm); fewer flowers per spikelet (3-4 cf. (2-)3-5(-8); smaller lower glume size range (2.0-3.5 cf. 2.0-4.5 mm), with the lower glume bearing 5 rather than 3-nerves; 5 rather than 5-7-nerved lemma; and differences from P. anceps in the overall DNA content and nrDNA ITS sequence.

Flowering

September - January

Fruiting

November - May

Propagation Technique

Easily grown from fresh seed and by division of established plants. A very attractive small grass excellent for wet or dry sites, in full sun or semi-shade. It is moderately cold tolerant.

Threats

Not Threatened. Listed because it is a narrow range endemic fo the Kermadec Islands group. It is abundant on Raoul but scarce on Macauley Island

Chromosome No.

2n = 28

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 6 Dec 2014