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 projectum

HABIT Perennial; caespitose. Culms erect; 30–90 cm long. Leaf-sheaths loose; pilose. Ligule an eciliate membrane. Leaf-blades flat, or involute; 4–10 cm long; 2–2.5 mm wide. Leaf-blade surface pubescent.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; 10–15 cm long; 1–2 cm wide.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 6–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 5–5.2 mm long; 0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein ciliolate. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 6–6.5 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein ciliolate. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 6 mm long; membranous; shiny; keeled; 5 -veined. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.66 way up back of lemma; geniculate; 5–6 mm long overall; with a straight or slightly twisted column. Lateral lemma awns arising on apex of lobes; 0.5–1 mm long. Palea gaping; 5 mm long; hyaline. Palea keels scaberulous. Palea apex erose.

FLOWER Anthers 3; 1.4–1.6 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: southwest USA.

NOTES Aveneae. Louis-Marie 2005.

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