GrassBase - The Online World Grass Flora


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

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

Poa pedersenii

HABIT Perennial; caespitose. Culms 25–35 cm long. Leaf-sheaths longer than adjacent culm internode; glabrous on surface. Ligule an eciliate membrane; 1.5–2 mm long; 0.3–0.5 mm long on basal shoots; truncate. Leaf-blades 5–20 cm long; 1.2–1.5 mm wide; stiff. Leaf-blade surface glabrous. Leaf-blade margins with tufts of hair.

INFLORESCENCE Dioecious. Inflorescence a panicle.

Panicle contracted; linear; 5.5–7 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 5.5–6 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 3.5–4.5 mm long; 0.9 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume surface scabrous; rough on veins. Lower glume apex acuminate. Upper glume lanceolate; 4.2–5 mm long; 0.9 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume margins scabrous. Upper glume apex acuminate.

FLORETS Fertile florets female. Fertile lemma lanceolate; 4.5–5.5 mm long; 1.6 mm wide; membranous; keeled; 5 -veined. Lemma margins ciliate; hairy below. Lemma apex acuminate. Palea 3.5–4.5 mm long. Palea keels scabrous; ciliate; adorned below. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 1.6–2 mm long. Staminodes present; 0.3–2 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

MALE Male inflorescence similar to female. Male spikelets resembling female; 4 flowered; with rudimentary apical florets; lanceolate; 4.8–6.5 mm long. Male spikelet glumes 2; lanceolate; 2.4–5.2 mm long. Male spikelet lemma 3.8–4 mm long; 5 -veined.

DISTRIBUTION South America: southern South America.

NOTES Poeae. Nicora 2001.

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