Aristida pittieri

HABIT Perennial; caespitose; clumped densely. Basal innovations intravaginal. Culms erect; 15–30 cm long; 0.5 mm diam. Culm-internodes glaucous. Lateral branches lacking. Leaf-sheaths mostly shorter than adjacent culm internode; smooth. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs. Leaf-blades filiform; convolute; 6–7 cm long; 0.5–1 mm wide. Leaf-blade surface scabrous; puberulous; hairy adaxially. Leaf-blade margins ciliate. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear, or lanceolate; 6–16 cm long. Primary panicle branches appressed, or ascending; 1–2 -nate. Panicle axis smooth, or scaberulous. Panicle branches capillary.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 6.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5 mm long; pubescent; obtuse, or acute.

GLUMES Glumes similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate; 5 mm long; 0.75 length of upper glume; membranous; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex dentate; 2 -fid; acute; mucronate. Upper glume lanceolate; 6.5 mm long; membranous; 1 -veined. Upper glume primary vein smooth. Upper glume lateral veins absent. Upper glume apex dentate; 2 -fid; acute; mucronate.

FLORETS Fertile lemma linear; subterete; 7 mm long; coriaceous; without keel; 3 -veined. Lemma surface scaberulous; rough above. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn with 18–20 mm long limb. Lateral lemma awns 18–20 mm long; subequal to principal.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; fusiform; without sulcus. Hilum linear.

DISTRIBUTION South America: northern South America and western South America.

NOTES Aristideae. Henrard 1995.

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