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 hygrometrica

HABIT Annual; caespitose; clumped loosely. Culms erect, or geniculately ascending; 29–84 cm long. Culm-internodes smooth; distally glabrous. Lateral branches lacking, or sparse. Leaf-sheaths smooth; glabrous on surface, or pilose. Leaf-sheath oral hairs ciliate; 1–2 mm long. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades curled, or flexuous; filiform; involute; 11–27 cm long; 0.8–1.2 mm wide. Leaf-blade surface scabrous; rough adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 14.4–35 cm long; 7–15 cm wide. Primary panicle branches 2 -nate; 2–3.5 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 25–43 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 4–6 mm long; pubescent; pungent. Floret callus hairs 0.4–1.3 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 13.5–23 mm long; 0.5–0.6 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex emarginate, or obtuse. Upper glume lanceolate; 25–42.6 mm long; 2.5–3 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex emarginate; mucronate, or awned; 1 -awned. Upper glume awn 0.5–3.5 mm long.

FLORETS Fertile lemma lanceolate; subterete; 8–16 mm long; coriaceous; without keel; 3 -veined. Lemma margins convolute; covering most of palea. Lemma apex acute; awned; 3 -awned. Principal lemma awn 3-branched; flat below; with 85–150 mm long limb; with twisted column; deciduous; abscissing from top of lemma. Column of lemma awn 53–85 mm long. Lateral lemma awns 81–140 mm long; subequal to principal. Palea 0.2 length of lemma; without keels.

FLOWER Anthers 3; 2 mm long.

FRUIT Caryopsis with adherent pericarp; 6.6–8.5 mm long. Hilum linear; 0.33 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Aristideae. Simon 1993.

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