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.

Eustachys swalleniana

HABIT Perennial; caespitose. Rhizomes short. Basal innovations intravaginal; flabellate. Culms erect; 26–105 cm long; 2–3 -noded. Culm-internodes elliptical in section. Culm-nodes brown; glabrous. Lateral branches lacking. Leaf-sheaths keeled; striately veined; smooth; glabrous on surface. Ligule a fringe of hairs; 0.2–0.5 mm long. Leaf-blades flat, or conduplicate; 6–11 cm long; 3–5 mm wide. Leaf-blade surface glabrous. Leaf-blade margins scabrous. Leaf-blade apex obtuse; apiculate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–6; digitate; unilateral; 5.5–12 cm long. Spikelet packing broadside to rhachis; crowded; regular.

Spikelets pectinate; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets obovate; laterally compressed; 2–2.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus glabrous.

GLUMES Glumes persistent; dissimilar; shorter than spikelet; thinner than fertile lemma; gaping. Lower glume lanceolate; 1.1–1.8 mm long; 0.9 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume oblong; 1.3–2 mm long; 0.8 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex emarginate, or obtuse; mucronate, or awned; 1 -awned. Upper glume awn subapical; 0.4–0.6 mm long.

FLORETS Fertile lemma ovate; laterally compressed; 2–2.5 mm long; chartaceous; dark brown; keeled; 3 -veined. Lemma midvein eciliate, or ciliolate. Lemma surface pubescent. Lemma margins ciliate. Lemma hairs 0.3 mm long. Lemma apex obtuse. Palea 2 mm long; 2 -veined. Palea keels smooth, or scaberulous; adorned above; with 0.5 of their length adorned. Rhachilla extension 0.5–0.8 mm long. Apical sterile florets 1 in number; barren; elliptic; 1.5–2 mm long. Apical sterile lemmas scabrous; obtuse.

FLOWER Lodicules 2; 0.2 mm long. Anthers 3; 0.6 mm long.

FRUIT Caryopsis with adherent pericarp; trigonous; 1 mm long. Embryo 0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Cynodonteae. Molina 2002.

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