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 obscura

HABIT Perennial; caespitose. Culms 25–40 cm long. Culm-internodes smooth; distally pubescent. Lateral branches ample. Leaf-sheaths antrorsely scabrous; pubescent. Leaf-sheath oral hairs bearded; 3 mm long. Ligule a fringe of hairs; 0.5 mm long. Collar pilose. Leaf-blades 10–25 cm long; 2–3 mm wide. Leaf-blade surface scabrous; rough adaxially; pubescent; hairy adaxially.

INFLORESCENCE Inflorescence a panicle. Peduncle elliptic in section.

Panicle open; ovate; loose; 7–15 cm long; 5–10 cm wide. Panicle branches scaberulous, or scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 13–21 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; pubescent; acute.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 6–15 mm long; 0.4–0.7 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface asperulous, or scabrous. Lower glume apex acute, or acuminate; awned; 1 -awned. Lower glume awn 1–3 mm long. Upper glume lanceolate; 13–21 mm long; 1.5–1.8 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface asperulous, or scabrous. Upper glume apex acute, or acuminate; awned; 1 -awned. Upper glume awn 1–3 mm long.

FLORETS Fertile lemma lanceolate; subterete; 11–14 mm long; coriaceous; purple; without keel; 3 -veined. Lemma surface scabrous; rough generally. Lemma margins convolute; covering most of palea. Lemma apex acute; awned; 3 -awned. Principal lemma awn with 15–40 mm long limb; without a column; persistent. Lateral lemma awns 23–38 mm long; subequal to principal. Palea 0.2 length of lemma; without keels.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp; 6–10 mm long. Hilum linear; 0.5 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Aristideae. Simon 1993.

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