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.

Sporobolus macrospermus

HABIT Annual; caespitose. Culms erect; 15–35 cm long. Culm-internodes solid; distally glabrous. Lateral branches sparse; arising from lower culm. Leaves mostly basal. Leaf-sheaths without keel; glabrous on surface; outer margin glabrous, or hairy. Ligule a fringe of hairs; 0.1–0.2 mm long. Leaf-blades 5–10 cm long; 2–4 mm wide. Leaf-blade margins tuberculate-ciliate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong; 9–11 cm long; 2–5 cm wide. Primary panicle branches spreading; whorled at most nodes. Panicle branches eglandular, or glandular (glands less than 0.5mm diam); smooth, or scaberulous.

Spikelets appressed; solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; (1.5–)1.7–2(–2.4) mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes deciduous; shorter than spikelet, or reaching apex of florets, or exceeding apex of florets. Lower glume linear; 0.7 mm long; 0.33–0.5 length of upper glume; membranous; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 1.5–2.4 mm long; 0.9–1.2 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 1.7–2 mm long; membranous; without keel; 1 -veined. Lemma apex acute. Palea 1 length of lemma; 2 -veined. Palea keels approximate.

FLOWER Anthers 3; 0.3–0.6 mm long.

FRUIT Caryopsis with free soft pericarp; 1.6–1.8 mm long; obtuse.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Eragrostideae. Fl Mes0-Am 1995.

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