GrassBase - The Online World Grass Flora

Descriptions

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

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

Aristida valida

HABIT Perennial; caespitose; clumped densely. Basal innovations intravaginal. Culms erect; robust; 70–80 cm long; 1.5 mm diam. Culm-internodes smooth. Leaf-sheaths 20 cm long; smooth, or scaberulous. Leaf-sheath oral hairs pubescent and ciliate. Ligule a fringe of hairs. Leaf-blades filiform; conduplicate, or involute; 10–20 cm long; 0.75 mm wide. Leaf-blade surface scabrous; rough on both sides. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 15–30 cm long; contracted about primary branches. Primary panicle branches appressed, or ascending; 2 -nate; 4–8 cm long. Panicle axis scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 5 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 18–23 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; 10.5–13.5 mm long; 0.66 length of upper glume; membranous; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute; awned; 1 -awned. Lower glume awn 2 mm long. Upper glume linear; 18–23 mm long; membranous; 1 -veined. Upper glume primary vein smooth. Upper glume lateral veins absent. Upper glume apex acute; awned; 1 -awned. Upper glume awn 2 mm long.

FLORETS Fertile lemma linear; subterete; 11–13 mm long; coriaceous; purple; without keel; 3 -veined. Lemma margins convolute; covering most of palea. Lemma apex with a short cylindrical neck; awned; 3 -awned. Principal lemma awn 3-branched; with 40–70 mm long limb. Lateral lemma awns ascending, or gyrate; 40–70 mm long; subequal to principal.

FLOWER Anthers 3.

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

DISTRIBUTION South America: southern South America.

NOTES Aristideae. Henrard 1995.

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