Stipa rigidiseta

HABIT Perennial; caespitose. Culms erect; 30–50 cm long. Ligule an eciliate membrane; 4 mm long. Leaf-blades filiform; convolute; 25–45 cm long; 0.5 mm wide. Leaf-blade surface ribbed; scabrous; glabrous. Leaf-blade apex pungent.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; 6–15 cm long. Panicle axis with lower internodes 2–4 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.5–4 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 4 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief; 0.3 mm long; pubescent; obtuse.

GLUMES Glumes persistent; similar; reaching apex of florets, or exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 3.2 mm long; 0.8 length of upper glume; membranous; without keels; 3–5 -veined. Lower glume apex acuminate. Upper glume lanceolate; 4 mm long; membranous; without keels; 3–5 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; subterete; 3–4 mm long; membranous; without keel; 5 -veined. Lemma surface pubescent; hairy all along. Lemma margins flat; covering most of palea. Lemma apex awned; 1 -awned. Principal lemma awn straight; 6–10 mm long overall; limb puberulous. Palea 2.5–2.9 mm long; 1 length of lemma; 2 -veined; without keels.

FLOWER Lodicules 3; 0.6 mm long. Anthers 3; anther tip smooth. Stigmas 2. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; fusiform. Hilum linear.

DISTRIBUTION South America: western South America.

NOTES Stipeae. Matthei 1995.

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