Poa tennantiana
Common names
muttonbird poa
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Grasses
Detailed description
Yellow-green, rather stout, stiff-leaved, perennial tussock-forming grass up to 1 m tall, arising from a strong rhizomatous base covered by abundant fibrous remnants of leaf-sheaths; branching intravaginal; leaf-blades persistent. Leaf-sheath submembranous, striate, densely, retrorsely, minutely pubescent-scabrid between ribs in basal leaves, glabrous in cauline leaves, very light brown, later becoming darker and shredding into fibres. Ligule 6–16 mm, apically glabrous, entire, narrowed to a long fine point, abaxially short-pubescent. Leaf-blade 160–380 x 4.5–9.0 mm, flat, finely striate, abaxially smooth, adaxially minutely papillose, very rarely minutely ciliate-scabrid on ribs; margins ciliate-fimbriate for a short distance above ligule, otherwise glabrous, gradually narrowed to straight-sided acute tip. Culm 150–330 mm, internodes glabrous. Panicle 90–160 mm, broad, dense but much-branched, upper branches almost completely hidden by numerous, rather small spikelets, lower branches naked towards base; rachis smooth, branches and pedicels ± scabrid to occasionally smooth. Spikelets 3.5–4.5 mm, 2–3-flowered, light brown. Glumes subequal, ovate-lanceolate, acute, glabrous; lower 2.0–2.5 mm, 1-nerved, upper 2.5–3.0 mm, 3-nerved; midnerve near tip and margins with sparse prickle-teeth. Lemma 3.0–3.5 mm, 5-nerved, ovate-elliptic, minutely pubescent-scabrid, nerves longer ciliate on lower ⅓, acute, or midnerve very shortly excurrent. Palea 2.5–3.0 mm, keels scabrid in upper ½, interkeel smooth or with a few prickle-teeth. Callus glabrous. Rachilla c. 0.5 mm, glabrous; prolongation twice as long. Lodicules 0.5–0.8 mm. Anthers 1.0–1.5 mm. Seed 1.5 × 0.5 mm.
Similar taxa
Similar to Poa foliosa (Hook.f.) Hook.f. which is a superficially similar southern New Zealand robust grass of coastal areas, especially near sea bird nesting grounds. Poa tennantiana differs from P. foliosa by its monoecious rather than dioecious habit, yellow-green rather than green leaves, by the lower leaf-sheaths scabrid between the nerves, rather than smooth, and by the glabrous rather than hairy (hairs crinkly in a prominent tuft) callus.
Distribution
Endemic. New Zealand: South (Otago (Taieri River Mouth), Stewart, Snares and Auckland Islands. It has not been seen on the Auckland Islands recently.
Habitat
Coastal usually in or near sea bird nesting grounds, on forest margins, clearings, in low scrub, on cliff faces and damp banks.
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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: RR
Threats
Not threatened. Listed because it is a narrow range endemic of mainly offshore island. It is abundant in most of its known locations with no obvious threats.
Detailed taxonomy
Family
Poaceae
Synonyms
Poa foliosa var. tennantiana (Petrie) Cheeseman
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
October–December
Fruiting
November–April
Propagation technique
Easily grown from fresh seed and rooted pieces. Dislikes humidity and will not flower or thrive in warm climates.
Other information
Where To Buy
Not commercially available.
Etymology
poa: Meadow grass
tennantiana: After Tennant, teacher and member of the 1907 expedition to the subantarctic islands
Manaaki Whenua Online Interactive Key
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
POATEN
Chromosome number
2n = 56
Previous conservation statuses
2017 | At Risk – Naturally Uncommon | Qualifiers: RR
2012 | At Risk – Naturally Uncommon | Qualifiers: 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.