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 cookii

HABIT Perennial; caespitose. Butt sheaths light brown, or dark brown; persistent and investing base of culm; with fibrous dead sheaths. Basal innovations intravaginal. Culms erect; 9–25 cm long. Culm-internodes smooth. Lateral branches lacking. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 4–7.5 mm long; lacerate; obtuse. Leaf-blades (9–)15–30 cm long; 3.5–5.5 mm wide; coriaceous. Leaf-blade midrib keeled beneath. Leaf-blade surface ribbed; grooved adaxially; scaberulous; rough adaxially. Leaf-blade margins smooth.

INFLORESCENCE Monoecious (gynomonoecious). Inflorescence a panicle.

Panicle contracted; oblong; 5–25 cm long. Primary panicle branches appressed. Panicle axis smooth. Panicle branches tuberculate.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–4 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 4.5–8.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1 mm long; smooth. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2–3 mm long; 0.66–0.75 length of upper glume; membranous; 1-keeled; 1(–3) -veined. Lower glume lateral veins absent, or obscure. Lower glume apex acute. Upper glume elliptic; 3–4 mm long; 0.66 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile florets with the lowest dissimilar. Lowest fertile lemma female. Fertile lemma elliptic, or oblong; lanceolate in profile; 4.8–6 mm long; membranous; light green; keeled; 5 -veined. Lemma midvein scabrous. Lemma surface smooth; puberulous; hairy at base; hairy on back. Lemma apex attenuate. Palea 4 mm long. Palea keels scabrous; ciliolate; adorned below. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; 1 mm long; membranous. Anthers 3; 2–3 mm long (lowest), or 0.2–0.4 mm long.

FRUIT Caryopsis with adherent pericarp; 1 mm long. Hilum punctiform.

DISTRIBUTION Antarctic: Subantarctic islands.

NOTES Poeae. Edgar 1997.

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