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.

Trisetum sibiricum

HABIT Perennial; caespitose; clumped loosely. Butt sheaths glabrous. Culms erect; 60–130 cm long; 3–4 -noded. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 2.5–3.5 mm long; lacerate. Leaf-blades 8–24 cm long; 3–8 mm wide. Leaf-blade surface pilose; hairy adaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 8–16 cm long; 2–4.5 cm wide. Primary panicle branches 3–5.5 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.8–4 mm long; scaberulous.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 6.3–8.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.8 mm long; pubescent; with 0.5–1 mm long hairs. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 3.5–4.5 mm long; 0.66 length of upper glume; hyaline; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 5.5–7.2 mm long; 1.1–1.2 length of adjacent fertile lemma; hyaline; 1-keeled; 3 -veined. Upper glume primary vein scaberulous. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 4.5–6.6 mm long; membranous; much thinner above; much thinner on margins; shiny; keeled; 5 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; curved; briefly coiled at base of limb; 6.5–9 mm long overall. Palea gaping; 5.4–6 mm long; hyaline. Palea keels scaberulous.

FLOWER Anthers 3; 2–3 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Europe: central and eastern. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, western Asia, China, Mongolia, and eastern Asia. North America: Subarctic.

NOTES Aveneae. Fl Turk 1993.

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