GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Deyeuxia jamesonii

HABIT Perennial. Rhizomes elongated. Culms erect; 6–24 cm long. Culm-internodes purple. Ligule an eciliate membrane; 1–2 mm long; lacerate. Leaf-blades curved; involute; 1–4.5 cm long; 1–2 mm wide; herbaceous, or coriaceous. Leaf-blade surface pubescent; hairy adaxially. Leaf-blade margins pubescent. Leaf-blade apex obtuse, or abruptly acute.

INFLORESCENCE Inflorescence a panicle; subtended by an inflated leaf-sheath.

Panicle spiciform; ovate; 1.8–4 cm long; 1–1.5 cm wide.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1 length of fertile spikelet; pubescent, or ciliate.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 5.7–6.3 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent. Floret callus hairs 0.5–1 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; purple; 1-keeled; 1 -veined. Lower glume primary vein ciliate. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 5.7–6.3 mm long; 1.3–1.4 length of adjacent fertile lemma; membranous; purple; 1-keeled. Upper glume primary vein ciliate. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 4–4.5 mm long; membranous; without keel. Lemma apex entire, or dentate; 2 -fid; truncate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.33 way up back of lemma; straight; 1.5–2 mm long overall. Rhachilla extension 1.5–2 mm long; villous; with 3–4 mm long hairs.

FLOWER Lodicules 2. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform. Disseminule comprising a floret.

DISTRIBUTION South America: western South America.

NOTES Aveneae. Tovar 1995.

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