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 bergii

HABIT Perennial. Rhizomes elongated. Basal innovations extravaginal and intravaginal. Culms robust; 50–100 cm long. Leaf-sheaths longer than adjacent culm internode; smooth. Ligule an eciliate membrane; 7–25 mm long; acute. Leaf-blades convolute; 25–50 cm long; 3–6 mm wide. Leaf-blade surface puberulous; densely hairy; hairy adaxially. Leaf-blade apex acute.

INFLORESCENCE Dioecious. Inflorescence a panicle.

Panicle contracted; elliptic; interrupted; 12–25 cm long. Primary panicle branches appressed; 2–5 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels smooth.

FERTILE SPIKELETS Spikelets comprising 6–7 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 10–14 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus woolly. Floret callus hairs 1 length of lemma.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume ovate; 6–8.5 mm long; 1 length of upper glume; membranous; much thinner on margins; 1-keeled; 3–5 -veined. Lower glume primary vein scabrous. Lower glume apex acuminate. Upper glume ovate; 6.5–10 mm long; 0.9 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 3–7 -veined. Upper glume primary vein scabrous. Upper glume apex acuminate.

FLORETS Fertile florets female. Fertile lemma elliptic; 7.5–9.5 mm long; membranous; keeled; 5–9 -veined. Lemma midvein without distinctive roughness, or scaberulous; ciliate; hairy below. Lemma margins ciliate; hairy below. Lemma apex acute. Palea keels pubescent; adorned below. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3.

FRUIT Caryopsis with adherent pericarp; ellipsoid; trigonous; 2.5–3 mm long. Hilum punctiform.

MALE Male inflorescence similar to female. Male spikelets resembling female.

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.