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.

Gouinia isabelensis

HABIT Perennial; culms solitary, or caespitose. Culms erect; 50–100 cm long; 0.5–3 mm diam.; 4–7 -noded. Culm-internodes distally glabrous. Lateral branches lacking. Leaf-sheaths longer than adjacent culm internode; antrorsely scabrous; glabrous on surface. Ligule a ciliolate membrane; 1–1.5 mm long. Collar glabrous, or pilose. Leaf-blades linear, or lanceolate; 10–30 cm long; 6–12 mm wide. Leaf-blade surface scaberulous; glabrous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–15; borne along a central axis; unilateral; 10–15 cm long. Central inflorescence axis 10–15 cm long. Rhachis angular. Spikelet packing lax.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear; angular; 2–6 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 9–12 mm long; 2–3 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1–1.5 mm long; scaberulous. Floret callus evident; pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture. Lower glume lanceolate; 3.5–5 mm long; 0.66 length of upper glume; membranous; 1-keeled; 1–5 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent, or distinct. Lower glume apex acuminate; mucronate, or awned; 1 -awned. Lower glume awn 0.5–1 mm long. Upper glume lanceolate; 5.5–7 mm long; 0.75 length of adjacent fertile lemma; membranous; 1-keeled; 3–7 -veined. Upper glume primary vein scabrous. Upper glume apex acuminate; mucronate, or awned; 1 -awned. Upper glume awn 0.5–1 mm long.

FLORETS Fertile lemma lanceolate; 7–9 mm long; membranous; keeled; 3–7 -veined. Lemma surface pilose; hairy below; hairy between veins. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn straight, or curved; 5–10 mm long overall. Palea 6–8 mm long; 2 -veined. Palea keels scabrous. Palea surface pilose; hairy on back. Apical sterile florets 1 in number; barren; lanceolate.

FLOWER Anthers 3; 0.5 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 2.5–3.5 mm long; dark brown.

DISTRIBUTION North America: Mexico.

NOTES Eragrostideae. Ortiz 2002.

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