GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Aristida pedroensis

HABIT Perennial; caespitose. Culms erect; robust; 80–130 cm long; 2.5–3 mm diam.; 4–5 -noded. Culm-internodes similar in length; distally glabrous. Culm-nodes swollen. Lateral branches lacking. Leaf-sheaths longer than adjacent culm internode; scaberulous. Leaf-sheath oral hairs scanty, or lacking. Ligule a fringe of hairs. Leaf-blades involute; 40–60 cm long; 2–3 mm wide. Leaf-blade venation with 6 secondary veins. Leaf-blade surface scabrous; rough on both sides. Leaf-blade margins cartilaginous. Leaf-blade apex attenuate.

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

Panicle contracted; linear. Primary panicle branches appressed; distant. Panicle axis scaberulous; glabrous, or puberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 3 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 12–14 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5 mm long; pubescent; obtuse.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume linear; 10 mm long; 0.75 length of upper glume; membranous; 1 -veined. Lower glume primary vein ciliolate. Lower glume lateral veins absent. Lower glume surface pubescent; hairy in lines. Lower glume apex dentate; 2 -fid; awned; 1 -awned. Lower glume awn 3–4 mm long. Upper glume linear; 12–14 mm long; 3–4 length of adjacent fertile lemma; membranous; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex dentate; 2 -fid; awned; 1 -awned. Upper glume awn 4–5 mm long.

FLORETS Fertile lemma linear; subterete; 3–4 mm long; coriaceous; without keel; 3 -veined. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn 3-branched; with 30 mm long limb; with twisted column. Column of lemma awn 10 mm long. Lateral lemma awns 30 mm long; subequal to principal. Palea hyaline; 0 -veined.

FLOWER Lodicules 2. Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: southern South America.

NOTES Aristideae. Henrard 1997.

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