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.

Eragrostis pectinacea

HABIT Annual. Butt sheaths green, or purple. Culms geniculately ascending, or decumbent; 15–40 cm long. Leaf-sheaths 3–6 cm long. Leaf-sheath oral hairs bearded; 2–2.5 mm long. Ligule a fringe of hairs; 0.5–1 mm long. Leaf-blades 5–18 cm long; 1–3 mm wide. Leaf-blade surface scaberulous; rough adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 7–20 cm long. Primary panicle branches simple. Panicle branches bearded in axils.

Spikelets appressed; solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 5–18 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 5–8 mm long; 1–1.5 mm wide; breaking up at maturity; rhachilla persistent; retaining paleas.

GLUMES Glumes deciduous; similar; shorter than spikelet. Lower glume lanceolate; 1 mm long; 0.6 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 1.5 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scaberulous. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma ovate; 1.5–2 mm long; membranous; keeled; 3 -veined. Lemma midvein scaberulous. Lemma lateral veins distinct; close to margins; extending close to apex. Lemma apex acute. Palea 1.5 mm long. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FRUIT Caryopsis with adherent pericarp; ellipsoid; laterally compressed; without sulcus; 0.8–1.2 mm long; dark brown, or red.

DISTRIBUTION Europe: southwestern. Asia-tropical: Malesia. Pacific: northwestern and north-central. North America: eastern Canada, northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Eragrostideae. = Eragrostis diffusa. Wagner 1993.

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