Puccinellia simplex

HABIT Annual; caespitose. Culms 7–20 cm long; 1–3 -noded. Leaf-sheaths open for most of their length. Ligule an eciliate membrane. Leaf-blades 2–4 cm long; 0.5–1.5 mm wide.

INFLORESCENCE Inflorescence a panicle, or composed of racemes (when depauperate).

Panicle contracted; linear; secund; 1–12 cm long. Primary panicle branches appressed; bearing spikelets almost to the base. Panicle branches stiff.

Racemes 1; single; unilateral.

Spikelets appressed; solitary. Fertile spikelets pedicelled. Pedicels oblong.

FERTILE SPIKELETS Spikelets comprising 4–6 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 6–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; eventually visible between lemmas.

GLUMES Glumes persistent; dissimilar; shorter than spikelet. Lower glume lanceolate; 1–2 mm long; 0.5 length of upper glume; herbaceous; without keels; 3 -veined. Lower glume apex obtuse. Upper glume lanceolate; 2–3 mm long; 0.7–0.8 length of adjacent fertile lemma; herbaceous; without keels; 3 -veined. Upper glume lateral veins thickened. Upper glume apex obtuse.

FLORETS Fertile lemma elliptic; 3.5 mm long; chartaceous; much thinner above; much thinner on margins; without keel; 5 -veined. Lemma lateral veins stopping well short of apex. Lemma surface pubescent. Lemma apex acute. Palea 1 length of lemma; 2 -veined. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION North America: southwest USA.

NOTES Poeae. WDC.

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