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 polyclados

HABIT Annual; caespitose. Culms geniculately ascending; 29–40 cm long. Culm-internodes smooth; distally glabrous. Leaf-sheaths scaberulous; glabrous on surface, or pilose. Leaf-sheath oral hairs ciliate; 0.5–1 mm long. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades filiform; involute; 8–11 cm long; 0.5–1.8 mm wide. Leaf-blade surface scabrous; rough on both sides; pilose; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 7–19 cm long; 8 cm wide. Primary panicle branches 3 -nate; 1–3.5 cm long. Panicle branches pilose.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 17–30 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 1.2–1.7 mm long; pubescent; pungent. Floret callus hairs 0.5–1 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 17–30 mm long; 1.3–1.5 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface glabrous, or pubescent. Lower glume apex emarginate, or obtuse; awned; 1 -awned. Lower glume awn 2–4 mm long. Upper glume lanceolate; 13–20 mm long; 2 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface glabrous, or pubescent. Upper glume apex emarginate, or obtuse; awned; 1 -awned. Upper glume awn 1–2 mm long.

FLORETS Fertile lemma lanceolate; subterete; 7–8 mm long; coriaceous; pallid and light brown; mottled with last colour; without keel; 3 -veined. Lemma surface tuberculate; rough above. Lemma margins convolute; covering most of palea. Lemma apex acute; awned; 3 -awned. Principal lemma awn 3-branched; with 32–76 mm long limb; with twisted column; deciduous; abscissing from top of lemma. Column of lemma awn 15–35 mm long. Lateral lemma awns 26–70 mm long; subequal to principal. Palea 0.2 length of lemma; without keels.

FLOWER Anthers 3; 0.7 mm long.

FRUIT Caryopsis with adherent pericarp; 3.7–5.6 mm long. Hilum linear; 0.5–0.6 length of caryopsis.

DISTRIBUTION Asia-tropical: Malesia. Australasia: Australia.

NOTES Aristideae. Simon 1993.

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