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 gibbosa

HABIT Perennial; caespitose. Culms erect; 100–150 cm long; 1.5–2.5 mm diam.; 2–3 -noded. Culm-internodes smooth, or scaberulous. Culm-nodes swollen; pubescent. Lateral branches lacking. Leaf-sheaths ribbed; glabrous on surface; outer margin hairy. Ligule a ciliolate membrane; 0.3–0.5 mm long; pubescent on abaxial surface; truncate. Leaf-blades flat, or convolute; 15–30 cm long; 2–5 mm wide. Leaf-blade surface ribbed; pubescent; hairy abaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 15–30 cm long; 1.5–2 cm wide. Primary panicle branches 4–9 cm long. Panicle axis scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels flattened; 4–10 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 11–17 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; curved; 1–1.5 mm long; pubescent; pungent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume elliptic; 11–17 mm long; 1.3–1.4 length of upper glume; membranous; without keels; 3 -veined. Lower glume surface scabrous; rough generally, or on veins. Lower glume apex acute, or acuminate. Upper glume elliptic; 8–13 mm long; membranous; without keels; 5 -veined. Upper glume surface scabrous; rough generally, or on veins. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma oblong; subterete; gibbous; 4.5–6 mm long; cartilaginous; dark brown to black; without keel; 5 -veined. Lemma surface tuberculate; pilose. Lemma margins flat; covering most of palea. Lemma hairs white, or yellow. Lemma apex surmounted by a ring of hairs; with this appendage 0.8–1.3 mm long; awned; 1 -awned. Principal lemma awn eccentric; bigeniculate; 25–35 mm long overall; with twisted column. Middle segment of lemma awn 1–12 mm long. Column of lemma awn 5–8 mm long; pubescent. Palea 1 length of lemma; 2 -veined; without keels.

FLOWER Lodicules 3; 0.5–1.3 mm long. Anthers 3; 2.5–3 mm long; anther tip smooth. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; 3.5 mm long. Embryo 0.33 length of caryopsis. Hilum linear; 0.75 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Stipeae. Vickery etc 1994.

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