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.

Willkommia texana

HABIT Perennial; caespitose. Culms 20–40 cm long. Ligule a fringe of hairs. Leaf-blades flat, or involute; 2–10 cm long; 1–3 mm wide; stiff. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–20; borne along a central axis; unilateral; 2–3 cm long. Central inflorescence axis 4–15 cm long. Rhachis angular. Spikelet packing adaxial; 2 -rowed.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 4–5 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes lower persistent, upper deciduous; dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 2–3 mm long; 0.5–0.66 length of upper glume; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume elliptic; 4–5 mm long; 1.1 length of adjacent fertile lemma; hyaline; without keels; 1 -veined. Upper glume apex obtuse.

FLORETS Fertile lemma elliptic; 3.5–4.5 mm long; membranous; without keel; 3 -veined. Lemma surface pubescent. Lemma margins ciliate. Lemma apex acute; mucronate. Palea surface pilose; hairy on back.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: south-central USA. South America: southern South America.

NOTES Cynodonteae. Gould.

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