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 tuberifera

HABIT Perennial; culms solitary. Butt sheaths pallid. Culms erect; 15–30 cm long; 0.5–0.8 mm diam.; 2–4 -noded; swollen at the base; forming an ovoid corm. Leaf-sheaths tubular for much of their length; with 0.66–0.8 of their length closed; smooth. Ligule an eciliate membrane; 1 mm long; white; truncate, or obtuse. Leaf-blades 5–10 cm long; 0.7–2 mm wide. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle; comprising 4–15 fertile spikelets.

Panicle open; ovate; effuse; 2–15 cm long; 1.5–4 cm wide; bearing few spikelets. Primary panicle branches spreading; 1–2 -nate; 1–5 cm long; bearing 1–5 fertile spikelets on each lower branch. Panicle branches capillary; smooth.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 8–10 mm long; smooth.

FERTILE SPIKELETS Spikelets comprising 2–4 fertile florets; with diminished florets at the apex. Spikelets elliptic, or ovate; laterally compressed; 4.5–6 mm long; 2–3 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.8–1.5 mm long; smooth. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume ovate; 2.2–2.5 mm long; 0.75–0.9 length of upper glume; membranous; much thinner on margins; 1-keeled; 1 -veined. Lower glume primary vein smooth. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume ovate; 2.5–3 mm long; 0.75–0.9 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 3 -veined. Upper glume primary vein smooth. Upper glume apex acuminate.

FLORETS Fertile lemma ovate; 3–3.5 mm long; 1.4–1.6 mm wide; membranous; much thinner above; much thinner on margins; keeled; 5 -veined. Lemma surface pubescent; hairy below; hairy on veins. Lemma apex acute. Palea 2.2–2.8 mm long. Palea keels scabrous; ciliate; adorned with hairs below. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 0.6–0.8 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Asia-temperate: eastern Asia.

NOTES Poeae. Koyama 1994.

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