Trisetum tenuiforme

HABIT Perennial; caespitose; clumped loosely. Butt sheaths pubescent. Culms slender; 15–40 cm long. Culm-internodes distally glabrous. Ligule an eciliate membrane. Leaf-blades convolute; 3–6 cm long; 1 mm wide. Leaf-blade surface glabrous, or pubescent.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate, or oblong; 3–6 cm long; 0.5–1.5 cm wide.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels glabrous.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 4–6 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pubescent; with 0.5 mm long hairs. Floret callus pubescent. Floret callus hairs 0.3 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; 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; 0.9 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 4–5.5 mm long; membranous; shiny; keeled; 5 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5–0.6 way up back of lemma; curved; 2–2.5 mm long overall. Palea gaping; hyaline.

FLOWER Anthers 3; 2–2.5 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Europe: southeastern.

NOTES Aveneae. Fl Eur 1995.

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