Poa polyphylla
Common names
Kermadec Islands poa
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Grasses
Detailed description
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 65–200 × 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 ⅔ 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.
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.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | At Risk – Naturally Uncommon | Qualifiers: IE, RR
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.
Detailed taxonomy
Family
Synonyms
Poa anceps subsp. polyphylla (Hack.) Edgar
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
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.
Other information
Etymology
poa: Meadow grass
Manaaki Whenua Online Interactive Key
Chromosome number
2n = 28
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | At Risk – Naturally Uncommon | Qualifiers: IE, RR
2012 | At Risk – Naturally Uncommon | Qualifiers: IE, RR
2009 | At Risk – Naturally Uncommon
2004 | Range Restricted
Referencing and citations
References and further reading
Edgar E, Connor HE. 2000. Flora of New Zealand. Vol. V. Grasses. Manaaki Whenua Press, Christchurch, NZ. 650 p.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (June 2005). Description modified from Edgar and Connor (2000).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.