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 orurensis

HABIT Perennial; caespitose. Culms erect; 30–60 cm long. Leaf-sheaths longer than adjacent culm internode; glabrous on surface, or puberulous. Ligule an eciliate membrane; 5–8 mm long; acuminate. Leaf-blades filiform; involute; 15–30 cm long; 1–1.5 mm wide. Leaf-blade surface ribbed. Leaf-blade apex pungent.

INFLORESCENCE Inflorescence a panicle; exserted, or embraced at base by subtending leaf.

Panicle open; linear; 5–15 cm long. Primary panicle branches appressed.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 6.5–7.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.4–0.5 mm long; glabrous; unequally 2-toothed.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 6.5–7.5 mm long; 1 length of upper glume; membranous; without keels; 5 -veined. Lower glume surface asperulous. Lower glume apex acuminate. Upper glume lanceolate; 6–7 mm long; membranous; without keels; 5 -veined. Upper glume surface asperulous. Upper glume apex acuminate; mucronate.

FLORETS Fertile lemma lanceolate; asymmetrical; subterete; 4.2–4.6 mm long; membranous; light brown; without keel; 5 -veined. Lemma surface villous. Lemma margins flat; covering most of palea. Lemma hairs 2–2.5 mm long. Lemma apex awned; 1 -awned. Principal lemma awn curved; 3–5(–7) mm long overall; deciduous. Palea 3.5–4 mm long; 1 length of lemma; 2 -veined; without keels. Palea surface pubescent.

FLOWER Lodicules 3. Anthers 3; anther tip smooth.

FRUIT Caryopsis with adherent pericarp; fusiform; laterally compressed; 2.5–4 mm long. Hilum linear.

DISTRIBUTION South America: western South America.

NOTES Stipeae. Rojas 2004.

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