Trisetum agrostideum

HABIT Perennial; caespitose; clumped loosely. Culms 20–40 cm long. Culm-internodes distally glabrous. Leaf-sheaths pubescent. Ligule an eciliate membrane. Leaf-blades flat, or convolute; 7–15 cm long; 1–3 mm wide. Leaf-blade surface glabrous, or pubescent; hairy adaxially. Leaf-blade margins ciliate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate, or oblong; 3–7 cm long; 0.5–1 cm wide. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels glabrous.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 4.2–5.7 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pubescent; with 0.7 mm long hairs. Floret callus pubescent.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 0.75 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 1.1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 3.5–4.5 mm long; membranous; shiny; keeled; 5 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.66 way up back of lemma; curved; 4.5–7 mm long overall. Palea gaping; hyaline.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Europe: northern and eastern. Asia-temperate: Siberia and Soviet far east.

NOTES Aveneae. Fl Eur 1995.

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