Stipa webberi

HABIT Perennial; caespitose; clumped densely. Culms erect; 10–30 cm long. Culm-internodes solid. Leaves mostly basal. Ligule an eciliate membrane; 0.3–0.5 mm long; glabrous on abaxial surface. Leaf-blades elliptic; involute; 5–10 cm long; 0.5 mm wide. Leaf-blade surface scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; 4–7 cm long. Primary panicle branches appressed.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets oblong; subterete; 7–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus 0.3 mm long; bearded; unequally 2-toothed.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 7–9 mm long; 1 length of upper glume; membranous; without keels; 5 -veined. Lower glume lateral veins obscure. Lower glume surface asperulous. Lower glume apex acuminate. Upper glume lanceolate; 7–9 mm long; 1.2 length of adjacent fertile lemma; membranous; without keels; 5 -veined. Upper glume lateral veins obscure. Upper glume surface asperulous. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; subterete; 6–7 mm long; membranous; without keel. Lemma surface pilose. Lemma margins flat; covering most of palea. Lemma apex dentate; 2 -fid; with lobes 0.5–1 mm long; awned; 1 -awned. Principal lemma awn from a sinus; straight, or curved; 5–8 mm long overall; deciduous. Palea 1 length of lemma; coriaceous; 2 -veined; without keels.

FLOWER Lodicules 3; 1.5 mm long. Anthers 1.5 mm long; anther tip smooth. Stigmas 2.

DISTRIBUTION North America: northwest USA and southwest USA.

NOTES Stipeae. Fl Pac NW 1994.

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