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 yaganica

HABIT Perennial. Rhizomes elongated. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms 20–90 cm long. Culm-internodes distally glabrous. Lateral branches lacking. Leaves mostly basal; distichous. Leaf-sheaths keeled; smooth, or scaberulous. Ligule an eciliate membrane; 3–4 mm long; scaberulous on abaxial surface; acute. Leaf-blades flat, or conduplicate; 5–20 cm long; 4–5 mm wide; stiff. Leaf-blade surface scabrous; rough adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; equilateral, or nodding; 6–12 cm long. Panicle branches flexuous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 5–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 3.5–4 mm long; 0.9 length of upper glume; membranous; 1-keeled; 1–3 -veined. Lower glume lateral veins absent, or distinct. Lower glume apex acute. Upper glume ovate; 4–4.5 mm long; 0.9 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma ovate; 4.5–5.5 mm long; membranous; keeled; 5 -veined. Lemma midvein ciliate; hairy below. Lemma surface scabrous; rough on veins. Lemma margins ciliate; hairy below. Lemma apex acute. Palea 1 length of lemma. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 1.8–2 mm long.

FRUIT Caryopsis with adherent pericarp. 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.