Phalaris paradoxa

HABIT Annual. Culms erect, or geniculately ascending; 20–100 cm long. Ligule an eciliate membrane; 2–8 mm long. Leaf-blades 5–15 cm long; 2–9 mm wide; glaucous.

INFLORESCENCE Inflorescence a panicle; subtended by an inflated leaf-sheath; embraced at base by subtending leaf.

Panicle spiciform; oblong; tapering below; 4–10 cm long; 1.5–2.5 cm wide. Primary panicle branches accrescent to a central axis; with evident branchlets on axis. Panicle axis with rounded ribs; scaberulous; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets pedicelled, or sessile; 1 in the cluster; heteromorphic (smaller and sessile at base of panicle); on shorter pedicels than sterile. Companion sterile spikelets pedicelled; 6 in the cluster. Involucre composed of imperfect spikelets; cuneate; 7–10 mm long.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; elliptic, or cuneate (and deformed); 4–6 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes chartaceous; winged on keels; acute. Companion sterile spikelet lemmas 1; enclosed by glumes; 2 mm long.

FERTILE SPIKELETS Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; laterally compressed; 7–8 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume ovate; 7–8 mm long; 1 length of upper glume; chartaceous; 1-keeled; winged on keel; winged in the middle; 3 -veined. Lower glume apex setaceously attenuate. Upper glume ovate; 7–8 mm long; 2–3 length of adjacent fertile lemma; chartaceous; 1-keeled; winged on keel; winged in the middle; 3 -veined. Upper glume apex setaceously attenuate.

FLORETS Basal sterile florets similar; both vestigial. Fertile lemma ovate; 2.5–3.5 mm long; coriaceous; shiny; keeled; 5 -veined. Lemma surface glabrous, or pubescent (sparsely); hairy above. Lemma apex obtuse. Palea elliptic; coriaceous; 2 -veined; without keels.

FLOWER Anthers 3; 1–1.8 mm long.

FRUIT Caryopsis 2.5 mm long.

DISTRIBUTION Europe: southwestern, southeastern, and eastern. Africa: north, Macaronesia, northeast tropical, and south. Asia-temperate: Soviet far east, Soviet Middle Asia, Caucasus, western Asia, Arabia, and China. Asia-tropical: India. Australasia: Australia and New Zealand. Pacific: north-central. North America: northwest USA, southwest USA, and Mexico. South America: western South America and southern South America.

NOTES Aveneae. Fl Turk.

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