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 jacobsiana

HABIT Perennial. Culms 80–120 cm long. Leaf-sheaths puberulous. Leaf-sheath auricles erect. Ligule an eciliate membrane; 0.4–1 mm long; obtuse. Leaf-blades erect; filiform; conduplicate; 35–45 cm long; 0.5–0.8 mm wide; stiff. Leaf-blade surface ribbed; grooved adaxially; puberulous; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 10–20 cm long; 1–2 cm wide. Primary panicle branches 4–8 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 3–13 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 10–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 1.6–2.1 mm long; pubescent; acute. Floret callus hairs 0.6–0.7 mm long (white).

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 10–12 mm long; 1 length of upper glume; membranous; without keels; 3 -veined. Lower glume apex acuminate. Upper glume lanceolate; 9–12 mm long; membranous; without keels; 5 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; subterete; 6–8 mm long; coriaceous; without keel. Lemma surface pubescent. Lemma margins convolute; covering most of palea. Lemma hairs white; 0.4–0.5 mm long. Lemma apex dentate; 2 -fid; with lobes 0.4–0.8 mm long; awned; 1 -awned. Principal lemma awn bigeniculate; 38–49 mm long overall; with twisted column. Middle segment of lemma awn 4–9 mm long. Column of lemma awn 11–17 mm long; puberulous; with 0.1–0.15 mm long hairs. Palea 1 length of lemma; without keels. Palea surface pubescent; hairy on back.

FLOWER Lodicules 3; ovate; 1.1–1.5 mm long. Anthers 3; 3.2–3.3 mm long; anther tip smooth.

FRUIT Caryopsis with adherent pericarp; fusiform; 4.5–5 mm long. Embryo 0.25 length of caryopsis. Hilum linear; 0.66 length of caryopsis.

DISTRIBUTION Australasia: Australia.

NOTES Stipeae. Williams 2011.

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