Stipa ichu

HABIT Perennial; caespitose; clumped densely. Culms (50–)80–100 cm long. Culm-internodes smooth to scaberulous. Leaves basal and cauline; differentiated into sheath and blade. Leaf-sheaths wider than blade at the collar; smooth, or scaberulous; glabrous on surface. Leaf-sheath oral hairs bearded. Ligule an eciliate membrane; 0.7 mm long; hyaline; lacerate; truncate. Leaf-blades erect to ascending; filiform; conduplicate; 15–45 cm long; 0.5–0.9 mm wide; stiff. Leaf-blade surface scaberulous.

INFLORESCENCE Bisexual. Inflorescence a panicle.

Panicle contracted; lanceolate to elliptic; 18–40 cm long. Primary panicle branches bearing spikelets almost to the base.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels puberulous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets oblanceolate; subterete; 7–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief; straight to curved; 0.1 mm long; bearded; acute.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma; shiny. Lower glume lanceolate; 9–11 mm long; 1–1.1 length of upper glume; hyaline; pallid, or purple; without keels; 3 -veined. Lower glume margins flat. Lower glume apex setaceously attenuate. Upper glume lanceolate; 9–11 mm long; 3 length of adjacent fertile lemma; hyaline; pallid, or purple; without keels; 3 -veined. Upper glume apex setaceously attenuate.

FLORETS Fertile lemma linear to lanceolate; subterete; 2.5–3 mm long; membranous; dark brown; without keel; 5 -veined. Lemma surface pilose. Lemma margins flat; covering most of palea. Lemma apex surmounted by a ring of hairs; with this appendage 3–4 mm long; awned; 1 -awned. Principal lemma awn bigeniculate; 11–13 mm long overall; with 5–8 mm long limb; with twisted column; deciduous; abscissing from top of lemma; limb scabrous. Palea lanceolate, or oblong; tightly convolute around flower; 0.5 length of lemma; 2 -veined; without keels. Palea apex entire; obtuse.

FLOWER Lodicules 3; oblong; 0.5 mm long; membranous; obtuse. Anthers 3; 0.6–0.7 mm long; anther tip penicillate. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; fusiform. Hilum linear.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, northern South America, western South America, and southern South America.

NOTES Stipeae. TB.

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