GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Poa chathamica

HABIT Perennial; mat forming, or caespitose. Rhizomes elongated. Butt sheaths coriaceous. Basal innovations extravaginal. Culms rambling; 50–90 cm long. Lateral branches lacking. Leaf-sheaths keeled; smooth, or antrorsely scabrous; glabrous on surface. Ligule a ciliolate membrane; 0.5–1 mm long; pubescent on abaxial surface; truncate. Leaf-blades flat, or conduplicate; 5–30 cm long; 2.5–4.5 mm wide; coriaceous; light green. Leaf-blade surface ribbed; grooved adaxially; scabrous; glabrous. Leaf-blade margins cartilaginous; scabrous. Leaf-blade apex pungent.

INFLORESCENCE Inflorescence a panicle. Peduncle smooth.

Panicle open, or contracted; 5.5–12 cm long. Primary panicle branches appressed, or ascending, or spreading. Panicle branches with occasional prickles.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 6.5–14.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.5–1 mm long; glabrous, or pubescent. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 4.5–7.5 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume primary vein scabrous. Lower glume surface smooth, or scabrous. Lower glume margins ciliolate. Lower glume apex acute, or acuminate. Upper glume lanceolate; 4.5–8 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume surface smooth, or scabrous. Upper glume margins ciliolate. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma lanceolate, or elliptic; elliptic in profile; 4.5–9 mm long; membranous; keeled; 5 -veined. Lemma midvein ciliate; hairy below. Lemma surface scabrous; rough between veins; pubescent; hairy at base; hairy on veins. Lemma apex obtuse. Palea 3.5–7.5 mm long. Palea keels ciliate; adorned above. Palea surface puberulous; hairy on back. Rhachilla extension 1–2 mm long.

FLOWER Lodicules 2; 0.5–2 mm long; membranous; glabrous, or ciliate. Anthers 3; 1.2–1.7 mm long.

FRUIT Caryopsis with adherent pericarp; 2 mm long. Hilum punctiform.

DISTRIBUTION Australasia: New Zealand.

NOTES Poeae. Edgar 1995.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.