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.

Stipa rudis

HABIT Perennial; caespitose. Rhizomes absent, or short. Basal innovations extravaginal. Culms geniculately ascending; 60–120 cm long; 2–4 mm diam.; firm; 2–4 -noded. Culm-internodes terete; smooth, or scaberulous; distally pubescent. Culm-nodes swollen; pubescent. Lateral branches lacking. Leaf-sheaths inflated; ribbed; glabrous on surface, or puberulous; outer margin hairy. Leaf-sheath oral hairs ciliate. Ligule a ciliolate membrane; 0.5–2 mm long; scarious; pubescent on abaxial surface; truncate, or acute. Collar pilose. Leaf-blades involute; 20–40 cm long; 2–5 mm wide. Leaf-blade surface ribbed; scaberulous; rough abaxially; pubescent; densely hairy; hairy adaxially. Leaf-blade apex hardened.

INFLORESCENCE Inflorescence a panicle.

Panicle open, or contracted; linear; 25–50 cm long; 1.5–5 cm wide. Primary panicle branches 7–15 cm long. Panicle axis smooth, or scabrous. Panicle branches terete; scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels angular; 5–15 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 8–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; curved; 0.8–3.2 mm long; pubescent; pungent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume linear, or oblong; 8–15 mm long; 1 length of upper glume; membranous; without keels; 3 -veined. Lower glume lateral veins ribbed. Lower glume surface asperulous; rough on veins; glabrous to pubescent. Lower glume apex erose; truncate, or obtuse. Upper glume linear, or oblong; 7–14.5 mm long; membranous; without keels; 3–5 -veined. Upper glume lateral veins ribbed. Upper glume surface asperulous; rough on veins; glabrous, or pubescent. Upper glume apex erose; truncate, or obtuse.

FLORETS Fertile lemma linear, or lanceolate; subterete; 5–11.5 mm long; coriaceous; dark brown; without keel; 5 -veined. Lemma surface tuberculate; rough above; pubescent; hairy below. Lemma margins flat; covering most of palea. Lemma apex awned; 1 -awned. Principal lemma awn bigeniculate; 20–90 mm long overall; with twisted column. Middle segment of lemma awn 4–15 mm long. Column of lemma awn 4.5–30 mm long; glabrous, or puberulous; with 0.05–0.3 mm long hairs. Palea 1 length of lemma; 2 -veined; without keels. Palea surface glabrous.

FLOWER Lodicules 3; 1–1.7 mm long. Anthers 3; 2–4 mm long; anther tip smooth. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; 3–6 mm long. Embryo 0.2–0.25 length of caryopsis. Hilum linear; 0.7–0.8 length of caryopsis.

DISTRIBUTION Australasia: Australia and New Zealand.

NOTES Stipeae. Vickery etc 1994.

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