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.

Soderstromia mexicana

HABIT Perennial. Stolons present. Culms 10–30 cm long. Ligule a fringe of hairs. Leaf-blades 2–7 cm long; 0.5–1 mm wide. Leaf-blade surface ribbed.

INFLORESCENCE Monoecious, or dioecious; with male and female spikelets in different inflorescences. Inflorescence composed of racemes.

Racemes 10–25; borne along a central axis; 0.3–0.4 cm long; bearing a triad of spikelets. Central inflorescence axis 1–5 cm long. Rhachis obsolete; deciduous from axis.

Spikelets in threes. Fertile spikelets pedicelled. Companion sterile spikelets sessile; 2 in the cluster. Male spikelets sessile; 3 in a cluster (2 of them reduced to a glume). Pedicels oblong; 0.5 mm long.

STERILE SPIKELETS Companion sterile spikelets represented by single glumes; cuneate; 2–2.5 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes membranous; distinctly veined; 3 -veined; entire; truncate; muticous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 3–3.5 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume cuneate; 2–2.5 mm long; 0.66 length of adjacent fertile lemma; membranous; without keels; 2 -veined. Upper glume apex erose; truncate.

FLORETS Fertile florets female. Fertile lemma elliptic; 3–3.5 mm long; cartilaginous; without keel; 3 -veined. Lemma apex lobed; 3 -fid; with outer lobes shorter; incised 0.33 of lemma length; acute. Apical sterile florets 1 in number; barren; rudimentary. Apical sterile lemmas awned; 3 -awned. Apical sterile lemma awns 3 mm long.

MALE Male inflorescence terminal; similar to female; of racemes along a central axis. Male spikelets resembling female; 2 flowered; lanceolate; 3–4 mm long. Male spikelet glumes 1; muticous. Male spikelet lemma 3 -veined; muticous.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Cynodonteae. WDC.

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