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.

Agrostis tolucensis

HABIT Perennial; caespitose; clumped densely. Culms erect; slender; 8–32 cm long; 0.5 mm diam.; 1–3 -noded. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 2.8–4.5 mm long. Leaf-blades erect; filiform; conduplicate; 5–10 cm long; 0.7–1 mm wide. Leaf-blade surface ribbed; scaberulous.

INFLORESCENCE Inflorescence a panicle. Peduncle 4–8 cm long.

Panicle spiciform; linear; 3–10 cm long; 0.3–0.8 cm wide. Primary panicle branches appressed; 0.5–2 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.5–3 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2.3–3.6 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; shiny; gaping. Lower glume oblong; 2.3–3.6 mm long; 1.1 length of upper glume; membranous; purple; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume oblong; 2.1–3.2 mm long; 1.1 length of adjacent fertile lemma; membranous; purple; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma ovate; 2–2.8 mm long; hyaline; without keel. Lemma lateral veins extending close to apex. Lemma apex dentate; 4 -fid; truncate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.33 way up back of lemma; geniculate; 2–2.8 mm long overall; with twisted column. Palea absent or minute.

FLOWER Lodicules 2; membranous. Anthers 3; 1 mm long; purple.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: southwest USA and Mexico. South America: Mesoamericana, northern South America, western South America, and southern South America.

NOTES Aveneae. Fl Costaric 1993.

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