The New Zealand Plant Conservation Network

Species

Poa aucklandica subsp. rakiura

Etymology

Poa: meadow grass
aucklandica: of the Auckland Islands
rakiura: Named after the Maori name for Stewart Island. Rakiura is derived from raki 'sky' and ura 'glowing' or 'blush'. One explanation for the name is because of the beautiful sunsets seen from the Island. Another possible explanation is the name is derived from Te Ura-Te Raki-tamou 'the blush of Te Raki Tamou, in reference to a story of the shame of a Maori chief who went to the island to court a woman and subsequently found out she had a husband.

Common Name(s)

Mt Anglem Poa

Current Conservation Status

2012 - Threatened - Nationally Critical

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 Critical
2004 - Range Restricted

Qualifiers

2012 - OL
2009 - OL

Authority

Poa aucklandica subsp. rakiura Edgar

Family

Poaceae

Flora Category

Vascular - Native

Structural Class

Grasses

Synonyms

None (first described in 1986)

Distribution

Endemic. New Zealand: Stewart Island (Mt Anglem)

Habitat

Near summit associated with Chionochloa crassiuscula (Kirk) Zotov subsp. crassiuscula grassland on rocks

Features

Dull green, slender, laxly tufted, slenderly rhizomatous perennial with narrow, ± erect leaves, ± reaching top of culms; branching extravaginal at plant base, intravaginal above; leaf-blades persistent. Leaf-sheath glabrous or sometimes shortly pubescent-scabrid near margins, very light green or pale brown, membranous, shredding into fibres. Ligule 0.5-2.0 mm, apically glabrous, ± obtuse and slightly erose, abaxially slightly scabrid. Leaf-blade 40.0-200.0 × 0.5-1.5 mm, flaccid, soft, flat to folded, underside smooth, upper surface minutely ciliate-scabrid on ribs; margins and midrib entirely smooth or with finely scabrid midrib and margins, tip curved. Culm 150-400 mm tall, slender, internodes usually slightly scabrid below panicle. Panicle 40-75 mm, lax, with few large spikelets borne singly at tips of filiform, finely scabrid branches. Spikelets 5.5-7.5 mm, 3-5-flowered, brownish green or greenish purple. Glumes ± unequal, elliptic, acute; smooth, but occasionally scabrid on midnerve near tip; lower 3.0-4.5 mm, 3-nerved, upper 4-5 mm, 3-(5)-nerved. Lemma 3.5-4.5 mm, oblong-elliptic, obtuse, 5-7-nerved, nerves minutely scabrid with a few short hairs near base of midnerve and outer lateral nerves, internerves glabrous, often scabrid towards tip. Palea 3-4 mm, minutely closely scabrid on keels, smooth elsewhere. Callus with very small tuft of long crinkled hairs. Rachilla c. 1 mm, sparsely scabrid; prolongation to twice as long. Lodicules 0.5-0.7 mm. Anthers 0.5-0.7 mm. Seeds 1.5 × 0.7 mm.

Similar Taxa

Allied to Poa aucklandica Petrie subsp. aucklandica and P. aucklandica subsp. campbelliensis (Petrie) Edgar. The first subspecies is confined to the Auckland Islands and differs from subsp. rakiura by its smaller tufted habit, with culms up to 300 cf. 400 mm tall in subsp. aucklandica, occasionally finely pubescent-scabrid, rather strictly glabrous leaf-sheath, shorter ligule (up to 1.3 cf. 2.0 mm) and shorter leaves (up to 160 mm cf. 200 mm), larger panicle (up to 80 mm cf. 75 mm), subequal rather than ± unequal glumes and other minor differences in the glume ornamentation, lemma, palea and anther size ranges. Poa aucklandica subsp. campbelliensis differs by its restriction to Campbell Island, it is a much smaller plant with closely packed shorter culms (up to 100 cf. 400 mm), longer leaves (up to 50 cf. 200 mm), smaller panicle up to 50 cf. 75 mm, and other minor differences in the glume ornamentation, lemma, palea and anther size ranges.

Flowering

Unknown - insufficiently studied and collected

Fruiting

Unknown - insufficiently studied and collected

Propagation Technique

Unknown.

Threats

A very localised, naturally uncommon, range restricted endemic known only from a small area near the summit of Mt Anglem. At present there is no evidence of decline but the population needs monitoring to ascertain trends. No obvious threats are evident at its sole known site which is within a Nature Reserve.

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 7 Jan 2014