Stipa perplexa

HABIT Perennial; caespitose. Basal innovations intravaginal. Culms erect; 30–70 cm long. Culm-internodes smooth, or scaberulous; distally glabrous. Leaf-sheaths longer than adjacent culm internode; smooth, or scaberulous; glabrous on surface; outer margin glabrous, or hairy. Ligule a ciliolate membrane; 0.3–0.8 mm long. Leaf-blades 1–3 mm wide. Leaf-blade surface scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 6–20 cm long; 1–2 cm wide. Primary panicle branches ascending.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 9–14 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5–0.85 mm long; pubescent; obtuse.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 9–14 mm long; 1.2–1.4 length of upper glume; hyaline; without keels; 3–5 -veined. Lower glume surface scabrous. Lower glume apex acuminate. Upper glume lanceolate; 7.5–10 mm long; 1.5–1.7 length of adjacent fertile lemma; hyaline; without keels; 3–5 -veined. Upper glume surface scabrous. Upper glume apex acuminate.

FLORETS Fertile lemma linear; subterete; 4.5–6.5 mm long; coriaceous; without keel; 5 -veined. Lemma surface pilose; hairy all along. Lemma margins convolute; covering most of palea. Lemma hairs 0.5–1.8 mm long. Lemma apex dentate; 2 -fid; with lobes 0.15–0.45 mm long; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 10–20 mm long overall; with a straight or slightly twisted column. Palea 2.5–3.75 mm long; without keels.

FLOWER Anthers 3; 2.25–4.2 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: south-central USA.

NOTES Stipeae. Hoge & Bark 2002.

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