Catapodium rigidum

HABIT Annual. Culms erect, or geniculately ascending; 2–30 cm long; 2–5 -noded. Ligule an eciliate membrane; 1–3 mm long; obtuse. Leaf-blades 1–10 cm long; 0.5–2 mm wide. Leaf-blade surface scaberulous.

INFLORESCENCE Inflorescence a panicle, or composed of racemes (in weak plants).

Panicle open, or contracted; linear, or lanceolate, or ovate; dense, or loose; secund; 1–8 cm long; 0.5–2.5 cm wide. Primary panicle branches simple; 0–2 cm long; bearing spikelets almost to the base. Panicle branches stiff; straight; angular.

Racemes single, or borne along a central axis; unilateral. Spikelet packing broadside to rhachis.

Spikelets appressed; solitary. Fertile spikelets pedicelled. Pedicels cuneate; 0.5–1.5 mm long.

FERTILE SPIKELETS Spikelets comprising 3–10 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 4–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes eventually visible between lemmas; scaberulous.

GLUMES Glumes persistent; dissimilar; shorter than spikelet. Lower glume lanceolate; 1.5–2 mm long; 0.9 length of upper glume; coriaceous; 1-keeled; 1–3 -veined. Lower glume lateral veins ribbed. Lower glume apex acute. Upper glume elliptic; 0.75 length of adjacent fertile lemma; coriaceous; 1-keeled; 3 -veined. Upper glume lateral veins ribbed. Upper glume apex acute.

FLORETS Fertile florets free at tip. Fertile lemma elliptic; oblong in profile; 2–2.5 mm long; coriaceous; without keel; 5 -veined. Lemma surface glabrous. Lemma apex obtuse. Palea 1 length of lemma; 2 -veined. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 0.3 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; ellipsoid; concavo-convex. Embryo 0.2 length of caryopsis. Hilum elliptic.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, northeast tropical, and south. Asia-temperate: Caucasus, western Asia, and Arabia. Australasia: Australia and New Zealand. North America: northwest USA, north-central USA, northeast USA, southwest USA, and southeast USA. South America: Caribbean, western South America, Brazil, and southern South America.

NOTES Poeae. CEH.

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