Trisetaria aurea

HABIT Annual; caespitose. Butt sheaths villous. Culms erect, or geniculately ascending; 5.5–12 cm long. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 1.5–3 mm long; obtuse. Leaf-blades 1.5–3.5 cm long; 1–2 mm wide. Leaf-blade surface glabrous, or pilose. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle; subtended by an unspecialized leaf-sheath, or an inflated leaf-sheath.

Panicle spiciform; ovate, or pyramidal; 1.6–3 cm long; 0.9–1.5 cm wide. Primary panicle branches 1.4–2 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.6–1.6 mm long; glabrous.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets cuneate; laterally compressed; 2.6–3.3 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; 0.3–0.4 mm long; pubescent. Floret callus pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 2.4–2.6 mm long; 0.9 length of upper glume; hyaline; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 2.8–3.2 mm long; 1.2–1.6 length of adjacent fertile lemma; hyaline; 1-keeled; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 1.7–2.7 mm long; membranous; much thinner on margins; keeled; 5 -veined. Lemma apex dentate; 2 -fid; acuminate; awned; 3 -awned. Principal lemma awn dorsal; geniculate; 1.7–4.3 mm long overall; with twisted column. Lateral lemma awns 0.3 mm long. Palea gaping; 1.5 mm long; hyaline.

FLOWER Lodicules 2; membranous. Anthers 3; 0.8–1.5 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Embryo 0.1–0.15 length of caryopsis. Hilum punctiform.

DISTRIBUTION Europe: southwestern and southeastern.

NOTES Aveneae. Fl Turk 1993.

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