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 utilis

HABIT Perennial; caespitose. Culms 53–130 cm long. Culm-internodes smooth, or scaberulous; distally pubescent. Culm-nodes glabrous. Lateral branches lacking, or sparse. Leaf-sheaths smooth, or scaberulous; glabrous on surface. Leaf-sheath oral hairs ciliate; 1.5–3 mm long. Ligule a fringe of hairs; 0.3–0.5 mm long. Leaf-blades curled, or flexuous; involute; 10–21 cm long; 1.5–2 mm wide. Leaf-blade surface smooth, or scaberulous; glabrous, or pubescent; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 15–48 cm long; 1–6 cm wide. Primary panicle branches 2–3 -nate; 4–8.5 cm long; naked below, or bearing spikelets almost to the base. Panicle branches scabrous; glabrous, or pubescent.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; compressed slightly; 8–20 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.4–0.7 mm long; pubescent; acute. Floret callus hairs 1 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 7.3–16 mm long; 0.9 length of upper glume; membranous; 1-keeled; 3–5 -veined. Lower glume surface smooth to scabrous. Lower glume apex acute, or acuminate; awned; 1 -awned. Lower glume awn 2.5–4 mm long. Upper glume lanceolate; 8.3–17 mm long; 0.9–1 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 2.5–4 mm long.

FLORETS Fertile lemma lanceolate; subterete; 8–20 mm long; coriaceous; without keel; 3 -veined. Lemma surface scabrous; rough above; glabrous, or pubescent; hairy above. Lemma margins involute; covering most of palea. Lemma apex acute; awned; 3 -awned. Principal lemma awn geniculate, or 3-branched; with 9–31 mm long limb; with twisted column; persistent. Column of lemma awn 5–9 mm long; glabrous, or puberulous. Lateral lemma awns 0–10 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. Hilum linear; 0.25 length of caryopsis.

DISTRIBUTION Asia-tropical: Papuasia. Australasia: Australia.

NOTES Aristideae. Simon 1993.

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