Stipa annua

HABIT Annual; caespitose. Culms erect; 10–20 cm long; 2 -noded. Ligule an eciliate membrane; 0.2 mm long. Leaf-blades flat, or convolute; 2–5 cm long; 0.5–1.5 mm wide. Leaf-blade surface ribbed; puberulous; hairy abaxially.

INFLORESCENCE Inflorescence a panicle; embraced at base by subtending leaf.

Panicle contracted; linear; 4–8 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–5 mm long; pubescent; hairy above.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 7 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief; 0.5 mm long; pubescent; pungent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; without keels; 3 -veined. Lower glume margins ciliolate. Lower glume apex acuminate. Upper glume lanceolate; 7 mm long; membranous; without keels; 3 -veined. Upper glume margins ciliolate. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; subterete; 5 mm long; membranous; without keel; 5 -veined. Lemma surface pubescent; hairy all along. Lemma margins flat; covering most of palea. Lemma apex surmounted by a ring of hairs; with this appendage 0.5–1.5 mm long; awned; 1 -awned. Principal lemma awn geniculate; 20–30 mm long overall; with twisted column. Column of lemma awn 10–15 mm long; hirtellous. Palea 1.5 mm long; 0.5 length of lemma; 2 -veined; without keels.

FLOWER Lodicules 2. Anthers 3; anther tip penicillate. Stigmas 2. Styles free to the base. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; fusiform; 2 mm long. Hilum linear; 0.75 length of caryopsis.

DISTRIBUTION South America: western South America.

NOTES Stipeae. Matthei 1995.

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