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 pruinosa

HABIT Perennial; caespitose; clumped loosely. Culms erect; 60–153 cm long. Culm-internodes glaucous; smooth; distally glabrous. Culm-nodes glabrous. Lateral branches sparse. Leaf-sheaths longer than adjacent culm internode; smooth; glabrous on surface. Leaf-sheath oral hairs lacking, or ciliate; 1–2 mm long. Ligule a fringe of hairs; 0.5–1 mm long. Collar glabrous, or pubescent. Leaf-blades straight, or flexuous; 20–40 cm long; 2–4.5 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous, or pubescent; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; lanceolate; continuous, or interrupted; 15–37 cm long; 2–4 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; 10–25 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; pubescent; acute.

GLUMES Glumes deciduous; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 10–25 mm long; 1.3–1.7 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface smooth to scabrous. Lower glume apex acute, or acuminate. Upper glume lanceolate; 7.6–15 mm long; 1.1–1.4 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex emarginate to acuminate.

FLORETS Fertile lemma lanceolate; subterete; 5.4–13.5 mm long; coriaceous; pallid, or light brown; mottled with last colour; without keel; 3 -veined. Lemma surface smooth, or scabrous; rough above. Lemma margins involute; covering most of palea; scabrous. Lemma apex acute; awned; 3 -awned. Principal lemma awn flat below; with 14–48 mm long limb; without a column; persistent. Lateral lemma awns 14–37 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; 5–8.3 mm long. Hilum linear; 0.4 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Aristideae. Simon 1993.

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