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 atropidiformis

HABIT Perennial; caespitose. Culms 10–30 cm long. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 2–3 mm long; lacerate; obtuse. Leaf-blades straight, or curved; conduplicate; 2–4 cm long; 2–3 mm wide. Leaf-blade venation prominent. Leaf-blade margins scabrous. Leaf-blade apex abruptly acute, or acute.

INFLORESCENCE Inflorescence a panicle; embraced at base by subtending leaf, or enclosed.

Panicle contracted; linear; 5–10 cm long. Primary panicle branches appressed; 1–4 cm long. Panicle axis scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–4 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 3.5–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.5–1 mm long. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet, or reaching apex of florets. Lower glume lanceolate; 3.5–5 mm long; 1 length of upper glume; membranous; much thinner on margins; 1-keeled; 1–3 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent, or distinct. Lower glume apex acute. Upper glume ovate; 3.5–5 mm long; 1.2–1.7 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Fertile lemma oblong; elliptic in profile; 2.5–3 mm long; membranous; much thinner on margins; keeled; 5 -veined. Lemma midvein scabrous. Lemma surface smooth, or scaberulous; rough above; pubescent. Lemma apex obtuse. Palea 1 length of lemma. Palea keels scabrous; adorned above. Palea surface glabrous, or pubescent; hairy on back. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 0.4–0.8 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 1.2–1.5 mm long. Hilum punctiform.

DISTRIBUTION South America: southern South America.

NOTES Poeae. Fl Pat 1995.

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