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 sorianoi

HABIT Perennial; caespitose. Butt sheaths yellow; pubescent. Culms 15–20 cm long; 0.3–0.5 mm diam.; 2–3 -noded. Culm-internodes antrorsely scabrous. Culm-nodes glabrous. Leaf-sheaths 5–7 cm long. Ligule an eciliate membrane; acute. Leaf-blades filiform; conduplicate; 8–10 cm long; 0.3–0.4 mm wide. Leaf-blade surface glabrous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle; comprising 10 fertile spikelets; exserted, or embraced at base by subtending leaf.

Panicle open; lanceolate; 3–7 cm long; bearing few spikelets.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2–7 mm long; scabrous; ciliate; hairy above.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 19–26 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 2 mm long; pubescent; pungent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 19–26 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex attenuate. Upper glume lanceolate; 19–26 mm long; membranous; without keels; 3 -veined. Upper glume apex attenuate.

FLORETS Fertile lemma lanceolate; subterete; 8–9 mm long; coriaceous; without keel; 5 -veined. Lemma surface pubescent; hairy below. Lemma margins convolute; covering most of palea. Lemma apex dentate; 2 -fid; with lobes 2 mm long; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 30–40 mm long overall; with twisted column. Column of lemma awn 11–14 mm long; plumose; with 5–6 mm long hairs. Palea 5–6 mm long; 2 -veined; without keels. Palea surface pubescent.

FLOWER Lodicules 3. Anthers 3; yellow, or purple; anther tip smooth. Stigmas 2. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; fusiform. Hilum linear.

DISTRIBUTION South America: southern South America.

NOTES Stipeae. Fl Pat 1995.

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