Stipa scribneri

HABIT Perennial. Culms erect; 30–70 cm long. Culm-internodes distally glabrous, or pubescent. Leaf-sheaths glabrous on surface. Leaf-sheath oral hairs ciliate. Ligule an eciliate membrane; 0.5–1 mm long. Leaf-blades flat; 15–25 cm long; 2–4 mm wide. Leaf-blade surface scaberulous; rough adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; dense; 10–25 cm long. Primary panicle branches appressed; 1–5 cm long. Panicle branches pubescent in axils.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 10–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 1 mm long; pubescent (tawny); unequally 2-toothed.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; pallid; without keels; 3 -veined. Lower glume surface asperulous. Lower glume apex attenuate. Upper glume lanceolate; 10–15 mm long; membranous; pallid; without keels; 3 -veined. Upper glume surface asperulous. Upper glume apex attenuate.

FLORETS Fertile lemma lanceolate; subterete; 8 mm long; membranous; pallid; without keel; 5 -veined. Lemma surface pubescent and pilose (longer above). Lemma margins flat; covering most of palea. Lemma hairs white; 1–2 mm long. Lemma apex awned; 1 -awned. Principal lemma awn bigeniculate; 14–20 mm long overall; with twisted column. Middle segment of lemma awn 3–5 mm long. Column of lemma awn 3–5 mm long; glabrous. Palea 0.4 length of lemma; 2 -veined; without keels.

FLOWER Lodicules 2. Anthers 3; anther tip smooth. Stigmas 2. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: northwest USA, southwest USA, and south-central USA.

NOTES Stipeae. N Amer Fl 1994.

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