GrassBase - The Online World Grass Flora

Descriptions

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

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

Poa exigua

HABIT Perennial; caespitose. Butt sheaths glossy. Basal innovations extravaginal. Culms 5–15 cm long. Lateral branches lacking. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 0.2–0.7 mm long; glabrous on abaxial surface; erose; truncate. Leaf-blades conduplicate; 1–6 cm long; 0.6–2 mm wide; glaucous. Leaf-blade venation indistinct. Leaf-blade surface smooth; glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle smooth, or scaberulous above.

Panicle contracted, or spiciform; linear; 0.5–2.5 cm long. Panicle axis scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 2.5–3.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.5 mm long; smooth. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume elliptic; 1.5–2.5 mm long; 1 length of upper glume; membranous; 1-keeled; 1(–3) -veined. Lower glume lateral veins absent, or obscure. Lower glume apex obtuse. Upper glume ovate; 1.5–2.5 mm long; 0.75–1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex obtuse.

FLORETS Fertile lemma lanceolate; elliptic in profile; 2–2.5 mm long; membranous; much thinner on margins; keeled; 5(–7) -veined. Lemma midvein scabrous. Lemma surface papillose; pubescent; hairy on veins. Lemma apex obtuse. Palea 1.5–2.3 mm long. Palea keels scabrous; adorned above. Palea surface smooth. Rhachilla extension 1 mm long.

FLOWER Lodicules 2; 0.4–0.5 mm long; membranous. Anthers 3; 0.2–0.5 mm long.

FRUIT Caryopsis with adherent pericarp; 1–1.3 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.