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 petrophila

HABIT Perennial; caespitose; clumped densely. Butt sheaths herbaceous; purple. Basal innovations intravaginal. Culms 20–70 cm long; 1–2 -noded. Culm-internodes terete; scaberulous; distally glabrous, or pubescent. Culm-nodes glabrous, or pubescent. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths smooth; pubescent. Ligule a ciliolate membrane; 2–3 mm long; pubescent on abaxial surface; truncate. Leaf-blades filiform; involute; 5–25 cm long; 0.5–0.7 mm wide; stiff. Leaf-blade surface pubescent.

INFLORESCENCE Inflorescence a panicle. Peduncle smooth.

Panicle open; elliptic; 5–13 cm long. Primary panicle branches 1–4 -nate; sparsely divided. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 3–8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 5–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes smooth. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume oblong; 0.9 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume primary vein scabrous. Lower glume surface scabrous. Lower glume apex acute. Upper glume oblong; 0.75–0.8 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume surface scabrous. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; elliptic in profile; 3–4 mm long; membranous; keeled; 5 -veined. Lemma midvein ciliate. Lemma surface scabrous; rough above; pubescent; hairy on back, or on veins. Lemma margins ciliate; hairy at base. Lemma apex obtuse. Palea 0.9 length of lemma. Palea keels ciliate; adorned above. Palea surface pubescent. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 2 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Australasia: Australia.

NOTES Poeae. Vickery.

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