Nassella caespitosa

HABIT Perennial; caespitose. Basal innovations extravaginal. Culms erect; 15–75 cm long; 0.5–1.25 mm diam.; 1–3 -noded. Culm-internodes smooth; distally glabrous. Culm-nodes swollen; brown; glabrous, or pubescent. Lateral branches lacking. Leaf-sheaths striately veined; glabrous on surface, or puberulous. Leaf-sheath oral hairs scanty, or ciliate. Ligule an eciliate membrane; erose; truncate, or obtuse. Leaf-blades filiform, or linear; convolute; 2.5–20 cm long; 0.5–5 mm wide. Leaf-blade midrib scarcely raised beneath. Leaf-blade venation with 6–20 secondary veins. Leaf-blade surface ribbed; scabrous; rough abaxially; glabrous, or puberulous; hairy abaxially. Leaf-blade margins ciliate. Leaf-blade apex attenuate.

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

Panicle open; linear, or elliptic; 5–25 cm long. Primary panicle branches 3 -nate; naked below, or bearing spikelets almost to the base. Panicle axis smooth. Panicle branches smooth, or scaberulous.

Spikelets appressed; solitary. Fertile spikelets pedicelled. Pedicels 1–10 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 4–5.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief; 0.2–0.3 mm long; pubescent; acute.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 4–4.5 mm long; 1 length of upper glume; membranous; without keels; 3 -veined. Lower glume apex acute. Upper glume lanceolate; 4–5 mm long; membranous; without keels; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma elliptic; subterete; 2–3.5 mm long; 0.5–1 mm wide; coriaceous; dark brown; without keel; 5 -veined. Lemma surface smooth; pubescent; hairy on back. Lemma margins convolute; covering most of palea. Lemma apex with a membranous corona and surmounted by a ring of hairs; awned; 1 -awned. Principal lemma awn bigeniculate; 5–9.5 mm long overall; with 2–8 mm long limb; with twisted column; persistent. Middle segment of lemma awn 1–4 mm long. Column of lemma awn 1–4 mm long. Palea lanceolate; 0.5–0.75 mm long; 0.2–0.33 length of lemma; 0 -veined; without keels.

FLOWER Lodicules 2. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION South America: southern South America.

NOTES Stipeae. Speg 1997.

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