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 tucumana

HABIT Perennial; caespitose; clumped densely. Basal innovations intravaginal. Culms erect; 12–20 cm long. Culm-internodes distally glabrous. Lateral branches lacking. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 2 mm long; erose. Leaf-blades flat, or conduplicate; 3–6 cm long; 0.5–1.5 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; 5–8 cm long. Primary panicle branches spreading; 1 -nate; 2–3 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 2–2.4 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.5 mm long. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume primary vein scabrous. Lower glume apex acute. Upper glume lanceolate; 2 mm long; 0.66 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 2 mm long; membranous; keeled; 5 -veined. Lemma midvein scabrous. Lemma surface puberulous; hairy below. Lemma apex acute. Palea 1.5 mm long. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 1; 0.5–0.8 mm long.

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

DISTRIBUTION South America: southern South America.

NOTES Poeae. Parodi 1997.

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