Stipa diegoensis

HABIT Perennial; caespitose. Culms erect; 70–100 cm long. Culm-internodes scaberulous; distally pubescent. Leaf-sheaths smooth, or scaberulous; glabrous on surface. Leaf-sheath oral hairs lacking. Ligule an eciliate membrane; 1–2 mm long; truncate, or obtuse. Leaf-blades flat, or involute; 15–40 cm long; 2–4 mm wide. Leaf-blade surface scabrous; rough abaxially; pubescent; hairy adaxially. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 15–30 cm long. Primary panicle branches appressed. Panicle branches glabrous in axils.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 9–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief; 0.5 mm long; pubescent; unequally 2-toothed.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 9–10 mm long; 1.1 length of upper glume; hyaline; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 8–9 mm long; hyaline; without keels; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma linear; subterete; 6.5–7.5 mm long; membranous; without keel; 5 -veined. Lemma surface pilose; with conspicuous apical hairs. Lemma margins flat; covering most of palea. Lemma hairs 1–2 mm long. Lemma apex emarginate; awned; 1 -awned. Principal lemma awn bigeniculate; 20–33 mm long overall; with twisted column. Column of lemma awn scabrous; glabrous. Palea 0.6 length of lemma; 2 -veined; without keels.

FLOWER Lodicules 2. Anthers 3. Stigmas 2. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: southwest USA and Mexico.

NOTES Stipeae. Man US Gr 1997.

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