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 exserta

HABIT Perennial; caespitose; clumped densely. Culms 45–75 cm long. Culm-internodes smooth; distally glabrous. Lateral branches fastigiate. Leaf-sheaths glabrous on surface. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs; 0.3 mm long. Leaf-blades filiform; involute; 4–8 cm long; 0.5 mm wide. Leaf-blade surface scabrous; rough adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted, or spiciform; linear; 10–15 cm long; 1 cm wide.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 7–11 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; pubescent; acute.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma. Lower glume lanceolate; 6.5–10 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume surface smooth to scabrous. Lower glume apex emarginate, or acute; awned; 1 -awned. Lower glume awn 0.5–1.3 mm long. Upper glume lanceolate; 6.7–10 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute, or acuminate; awned; 1 -awned. Upper glume awn 0.5–1.3 mm long.

FLORETS Fertile lemma lanceolate; subterete; 7–11 mm long; coriaceous; without keel; 3 -veined. Lemma surface scabrous; rough above. Lemma margins involute; covering most of palea; without distinctive roughness. Lemma apex acute; awned; 3 -awned. Principal lemma awn spreading; with 9.5–11 mm long limb; without a column; persistent. Lateral lemma awns spreading as much as principal; 8.5–10.5 mm long; shorter than principal. Palea 0.2 length of lemma; without keels.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; sulcate on hilar side; 5–6 mm long. Hilum linear; 0.2–0.3 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Aristideae. Simon 1993.

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