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.

Muhlenbergia majalcensis

HABIT Annual. Culms erect; slender; 18–36 cm long; 0.4–0.5 mm diam. Culm-internodes 1.5–6 cm long; smooth, or scaberulous. Leaf-sheaths 1–3.2 cm long; mostly shorter than adjacent culm internode; smooth, or scaberulous. Leaf-sheath auricles erect. Ligule an eciliate membrane; 1.5–2 mm long; erose, or lacerate; obtuse. Leaf-blades flat, or involute; 2–10 cm long; 0.7–1.4 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade surface scaberulous; rough abaxially; puberulous; hairy adaxially. Leaf-blade margins cartilaginous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong; effuse; 9–15 cm long; 3.5–9.5 cm wide. Primary panicle branches ascending, or spreading; 1–3 -nate; 1–6 cm long. Panicle axis 15–35 noded. Panicle branches capillary.

Spikelets pendulous, or deflexed; solitary. Fertile spikelets pedicelled. Pedicels filiform; recurved; 3–8 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 1.2–1.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets. Lower glume lanceolate; 1.2–1.5 mm long; 1 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 1.2–1.5 mm long; 1.2 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 1–1.2 mm long; membranous; light brown; without keel; 3 -veined. Lemma lateral veins obscure. Lemma apex obtuse; muticous. Palea 1–1.2 mm long; 1 length of lemma; 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.4–0.5 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 0.8–0.9 mm long; dark brown.

DISTRIBUTION North America: Mexico.

NOTES Eragrostideae. Peterson 1994.

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