Aira caryophyllea

HABIT Annual. Culms erect; 3–40(–55) cm long; 2–3 -noded. Leaves mostly basal. Ligule an eciliate membrane; 2–5 mm long; erose; obtuse. Leaf-blades filiform; involute; 0.5–5 cm long; 0.3–1 mm wide. Leaf-blade surface scaberulous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 1–12 cm long; (2–)3.5–10(–14) cm wide. Panicle branches capillary; terete; smooth.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; terete; 1–10 mm long; tip pyriform.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets oblong to ovate; laterally compressed; 2.4–3.1 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; 2.4–3.1 mm long; 1 length of upper glume; membranous; 1-keeled; keeled above; 1–3 -veined. Lower glume primary vein scaberulous. Lower glume apex acute. Upper glume ovate; 2.4–3.1 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; keeled above; 1–3 -veined. Upper glume primary vein scaberulous. Upper glume apex acute.

FLORETS Fertile lemma ovate; laterally compressed; lanceolate in profile; (1.8–)2–2.4(–2.6) mm long; cartilaginous; dark brown; 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; 2.6–3.6 mm long overall; with twisted column. Palea elliptic; 0.7 length of lemma; cartilaginous; 2 -veined. Palea apex obtuse.

FLOWER Lodicules 2; lanceolate; membranous. Anthers 3; 0.25–0.6 mm long. Stigmas 2; protandrous; laterally exserted.

FRUIT Caryopsis with adherent pericarp; fusiform; isodiametric; biconvex; estipitate; without sulcus; 1 mm long; smooth; apex unappendaged. Embryo 0.2 length of caryopsis. Hilum punctiform. Endosperm farinose. Disseminule comprising a floret.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, and southern tropical. Asia-temperate: Caucasus, western Asia, and China. Asia-tropical: India. Australasia: Australia and New Zealand. Pacific: south-central and north-central. North America: Subarctic, western Canada, northwest USA, northeast USA, southwest USA, southeast USA, and Mexico. South America: Mesoamericana, western South America, and southern South America. Antarctic: Subantarctic islands.

NOTES Aveneae. TAC.

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