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.

Aira uniaristata

HABIT Annual. Culms erect; 3–40 cm long. Leaves mostly basal. Ligule an eciliate membrane; entire. Leaf-blades filiform; involute; 0.5–5 cm long; 0.3–1 mm wide. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 1–12 cm long. Primary panicle branches branching divaricately. Panicle branches flexuous; terete; smooth.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; terete; 1–2 length of fertile spikelet.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets oblong to ovate; laterally compressed; 2–2.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes suppressed between florets (florets arising at about the same level). Floret callus pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume ovate; 2–2.5 mm long; 1 length of upper glume; membranous; 1-keeled; keeled above; 1–3 -veined. Lower glume lateral veins absent, or obscure. Lower glume apex acute. Upper glume ovate; 2–2.5 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; keeled above; 1–3 -veined. Upper glume lateral veins absent, or obscure. Upper glume apex acute.

FLORETS Fertile florets all alike, or with the lowest dissimilar. Lowest fertile lemma muticous, or awned. Fertile lemma ovate; laterally compressed; 1.5–2 mm long; cartilaginous; without keel; 5 -veined. Lemma lateral veins obscure. Lemma surface scaberulous; rough above. Lemma margins involute; covering most of palea. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.3–0.4 way up back of lemma; geniculate; 2–3 mm long overall; with twisted column. Palea cartilaginous; 2 -veined.

FLOWER Lodicules 2; lanceolate; membranous. Anthers 3; 1.3 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; apex unappendaged. Hilum punctiform. Endosperm farinose. Disseminule comprising a floret.

DISTRIBUTION Europe: southwestern.

NOTES Aveneae. Fl Eur 1997.

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