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.

Muhlenbergia watsoniana

HABIT Perennial; caespitose. Culms 40–70 cm long. Leaves mostly basal. Leaf-sheaths 3–6 cm long; longer than adjacent culm internode; without keel; smooth, or scaberulous; glabrous on surface. Ligule a ciliolate membrane; 0.5–0.7 mm long; truncate. Leaf-blades flat, or conduplicate; 10–20 cm long; 1.5–3 mm wide. Leaf-blade midrib keeled beneath. Leaf-blade surface scaberulous; pubescent; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; interrupted; 10–15 cm long; 1–2 cm wide. Primary panicle branches appressed, or ascending; 2.5–5 cm long; bearing spikelets almost to the base. Panicle axis pubescent.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.5–2 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 4–5.5 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; dissimilar; exceeding apex of florets. Lower glume lanceolate, or elliptic; 3–4 mm long; 0.75 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume surface hispidulous. Lower glume apex obtuse, or acute. Upper glume lanceolate, or elliptic; 4–5.5 mm long; 1.1–1.3 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume lateral veins obscure. Upper glume surface hispidulous. Upper glume apex entire, or dentate; 2 -fid; obtuse; muticous, or mucronate.

FLORETS Fertile lemma elliptic; 3–5 mm long; membranous; without keel; 3 -veined. Lemma surface pilose. Lemma hairs 0.5–0.7 mm long. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn flexuous; 20–25 mm long overall. Palea 0.9 length of lemma; 2 -veined. Palea surface pilose.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 2.7–2.9 mm long.

FRUIT Caryopsis with adherent pericarp; fusiform.

DISTRIBUTION North America: Mexico.

NOTES Eragrostideae. Fl Nov Gal 1994.

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