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 unispiculata

HABIT Perennial; cushion forming. Culms decumbent; 6–9.5 cm long; rooting from lower nodes. Lateral branches ample; intravaginal. Leaves distichous. Leaf-sheaths striately veined; smooth; glabrous on surface. Ligule an eciliate membrane; 1.5–3.1 mm long; obtuse. Leaf-blades spreading; triangular; conduplicate; 0.3–0.8 cm long; 0.5–0.7 mm wide; stiff; light green. Leaf-blade venation with 7–9 secondary veins. Leaf-blade surface smooth; glabrous. Leaf-blade margins scaberulous. Leaf-blade apex acute.

INFLORESCENCE Gynodioecious ("male", in this context, indicating the bisexual state). Inflorescence comprising only a few spikelets; comprising 1 fertile spikelets. Peduncle 0.5–0.6 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2(–3) fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 4.9–5.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes smooth. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume ovate; 1.3–1.6 mm long; 0.9 length of upper glume; herbaceous; much thinner on margins; 1-keeled; 1–3 -veined. Lower glume lateral veins absent, or obscure. Lower glume apex emarginate, or obtuse. Upper glume ovate; 1.6–2 mm long; 0.33 length of adjacent fertile lemma; herbaceous; with hyaline margins; 1-keeled; 1–3 -veined. Upper glume lateral veins absent, or obscure. Upper glume apex emarginate, or obtuse.

FLORETS Fertile lemma ovate; 4.9–5.5 mm long; herbaceous; much thinner above; much thinner on margins; keeled; 5(–7) -veined. Lemma lateral veins obscure; less than two thirds length of lemma. Lemma surface smooth. Lemma apex obtuse. Palea 1 length of lemma. Palea apex dentate; 2 -fid.

FLOWER Lodicules 2; lanceolate; 1.3–1.5 mm long; membranous. Anthers 3; 2.3–2.6 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; fusiform; sulcate on hilar side; 1.3–1.5 mm long. Embryo 0.33 length of caryopsis. Hilum elliptic.

DISTRIBUTION South America: western South America.

NOTES Poeae. Davidse et al 2011.

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