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 keckii

HABIT Perennial; caespitose; clumped densely. Basal innovations intravaginal. Culms 3–7(–22) cm long. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths open for most of their length; with 0.1–0.2 of their length closed. Ligule an eciliate membrane; 0–3 mm long; membranous; translucent; glabrous on abaxial surface, or scaberulous on abaxial surface; entire; obtuse, or acute. Collar glabrous. Leaf-blades involute; angular in section; 3–6(–12) cm long; firm. Leaf-blade venation distinct; comprising 7–15 vascular bundles. Leaf-blade surface smooth, or scabrous; rough adaxially; glabrous.

INFLORESCENCE Inflorescence a panicle; comprising 8–30 fertile spikelets; aerial, or shorter than basal leaves (mostly). Peduncle 2–12.5 cm long.

Panicle open, or contracted; lanceolate to ovate; 1.5–6(–10) cm long; 0.25–0.5 of culm length. Panicle branches terete, or angular; scabrous; rough throughout.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels (0.5–)1.5–5 mm long (mostly more than 2).

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.5–1 mm long; eventually visible between lemmas; smooth; glabrous, or sparsely hairy. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet; shiny. Lower glume lanceolate; 3–4.7 mm long; 0.9–1 length of upper glume; membranous; 1-keeled. Lower glume primary vein scabrous. Lower glume apex acute. Upper glume elliptic; 3–4.9 mm long; 0.9–1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Fertile florets bisexual (sometimes female). Fertile lemma lanceolate; widest at 0.15 of its length from base; elliptic in profile; 3–3.8–4.8 mm long; 1 mm wide; membranous; keeled; 5 -veined. Lemma midvein without distinctive roughness, or scaberulous; eciliate, or ciliate. Lemma lateral veins with distinct primaries but obscure intermediates. Lemma surface smooth to scaberulous; rough below and on veins, or between veins; pubescent; hairy between veins but central interspaces glabrous. Lemma apex truncate. Palea lanceolate; 1 length of lemma. Palea keels scabrous; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2. Anthers basifixed; 0.6–1.7(–2) mm long; purple. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: southwest USA.

NOTES Poeae. Soreng 2005.

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