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 pittieri

HABIT Perennial; caespitose. Culms geniculately ascending, or decumbent; 30–100 cm long; 1–3 mm diam. Culm-internodes distally glabrous. Culm-nodes pallid, or purple; glabrous. Lateral branches lacking. Leaf-sheaths smooth; glabrous on surface, or pilose; with reflexed hairs. Ligule an eciliate membrane; 1–3 mm long. Leaf-blades flat, or conduplicate; 10–30 cm long; 3–6 mm wide. Leaf-blade surface ribbed; pilose; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 10–25 cm long. Primary panicle branches ascending.

Spikelets appressed; solitary. Fertile spikelets pedicelled. Pedicels filiform; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 5–6 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose; acute. Floret callus hairs 0.5–1 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; gaping. Lower glume lanceolate; 1 length of upper glume; membranous; purple; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex attenuate. Upper glume lanceolate; 1.3 length of adjacent fertile lemma; membranous; purple; 1-keeled; 1–3 -veined. Upper glume primary vein scabrous. Upper glume lateral veins obscure. Upper glume apex attenuate.

FLORETS Fertile lemma lanceolate; 3.8–4.5 mm long; membranous; without keel; 5 -veined. Lemma lateral veins obscure. Lemma apex dentate; 2 -fid; with lobes 1.2–1.7 mm long; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5–0.66 way up back of lemma; geniculate; 4.2–5.7 mm long overall; with twisted column. Palea 2.8–3.5 mm long. Rhachilla extension 1.3–2.1 mm long; villous; with 2–5 mm long hairs.

FLOWER Lodicules 2. Anthers 2; 1.2–1.4 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; fusiform; 2 mm long. Hilum punctiform. Endosperm soft. Disseminule comprising a floret.

DISTRIBUTION South America: Mesoamericana, northern South America, and western South America.

NOTES Aveneae. Fl Costaric 1994.

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