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Info
Subfamily: Panicoideae
Genus etymology: Urochloa = "tail grass" [Greek] refering to the small tail (mucro) of the upper lemma of some species
Species etymology: arrecta = "erect" [Latin] refering to erect panicle branches
Photosynthetic type: C4 (warm season)
Nativity: naturalized - unclear
First recorded in Hawaiʻi: 2022
Map
Inflorescence
Plant
Habit
Spikelets
Description
Sprawling perennial; culms 50–130 cm. high, prostrate and rooting at the nodes below. Leaf-blades 5–25 cm. long, 5–15 mm. wide. Inflorescence of 4–15 racemes on an axis 5–25 cm. long; racemes 1–10 cm. long, bearing the spikelets singly in 2 regular rows on a narrow (0.5–1.5 mm. wide) winged rhachis with scabrid margins. Spikelets elliptic, 3–4.3 mm. long, glabrous, acute; lower glume 1/3–1/2 as long as the spikelet; upper glume not separated from the lower by an internode; upper lemma rugulose, obtuse, ± an obscure mucro.
(Description source: Clayton, W.D. & Renvoize, S.A. 1982. Flora of Tropical East Africa. Gramineae (Part 3). A.A. Balkema, Rotterdam. 448 pp. )
Plants perennial; stoloniferous. Culms 50–120 cm, branching and rooting at the lower nodes; nodes glabrous. Sheaths glabrous, margins ciliate; ligules about 1 mm; blades 5–15 cm long, 7–15 mm wide, glabrous, bases subcordate, margins scabrous. Panicles (5)9–18(25) cm long, 3–4 cm wide, with 4–10(15) spikelike primary branches in 2 ranks; primary branches (1)2–5(10) cm, axes 0.5–2 mm wide, glabrous, margins scabrous; secondary branches rarely present, pedicels shorter than the spikelets, mostly scabrous, apices with hairs. Spikelets (3)3.3–4.4 mm long, 1.4–1.7 mm wide, ellipsoid, solitary, imbricate, in 2 rows, appressed to the branches. Glumes scarcely separated; lower glumes 1.5–1.8 mm, glabrous, 5-veined, not clasping the base of the spikelets; upper glumes 3.4–4.1 mm, glabrous, 7-veined; lower florets staminate; lower lemmas 3.4–4.1 mm, glabrous, 5-veined; upper lemmas 2.7–3.5 mm long, 1.3–1.6 mm wide, apices rounded, incurved; anthers 1.6–1.8 mm. 2n = unknown.
(Description source: Barkworth, M.E., Capels, K.M., Long, S. & Piep, M.B. (eds.) 2003. Flora of North America, north of Mexico. Volume 25. Magnoliophyta: Commelinidae (in part): Poaceae, Part 2. Oxford University Press, New York. 783 pp http://floranorthamerica.org/Urochloa_arrecta )