Urochloa reptans (L.) Stapf

synonyms: Brachiaria reptans, Panicum prostratum, Panicum reptans


sprawling signalgrass


Info

Subfamily: Panicoideae
Genus etymology: Urochloa = "tail grass" [Greek] refering to the small tail (mucro) of the upper lemma of some species
Species etymology: reptans = "crawling" [Latin] refering to its habit
Photosynthetic type: C4 (warm season)
Nativity: naturalized - accidental
First recorded in Hawaiʻi: 1936

Map

 Distribution of Urochloa reptans in Hawaiʻi.

Inflorescence

Urochloa reptans Inflorescence
Urochloa reptans Inflorescence
Urochloa reptans Inflorescence
Urochloa reptans Inflorescence

Plant

Urochloa reptans Plant

Habit

Urochloa reptans Habit
Urochloa reptans Habit
Urochloa reptans Habit

Spikelets

Urochloa reptans Spikelets
Urochloa reptans Spikelets
Urochloa reptans Spikelets
Urochloa reptans Spikelets

Description

Plants annual; forming sprawling mats. Culms 10-35 cm, prostrate to decumbent; nodes glabrous or sparsely puberulent. Sheaths glabrous or sparsely pubscent, margins densely ciliate; ligules 0.5-1 mm; blades 2-6 cm long, 4-15 mm wide, adaxial surfaces glabrous or sparsely pubescent with papillose-based hairs, margins ciliate basally. Panicles 1.5-6(8) cm long, 4-5 cm wide, ovoid, with 3-16 spikelike branches in more than 2 ranks; primary branches 1-4 cm long, 0.2-0.5 mm wide, flat, scabrous; secondary branches occasionally present; pedicels shorter than the spikelets, scabrous, glabrous or with long hairs distally. Spikelets 1.8-2.2 mm long, 0.8-1 mm wide, mostly in pairs, in 2-4 rows, appressed to the branches. Glumes scarcely separate, rachilla internodes short, not pronounced; lower glumes 0.2-0.6 mm, 1/5 – 1/4 as long as the spikelets, 0-1-veined; upper glumes 1.7-2.1 mm, glabrous, 7-veined, without cross venation; lower florets sterile or staminate; lower lemmas 1.7-2.1 mm, glabrous, 5-veined, without cross venation; lower paleas present; upper lemmas 1.5-1.8 mm long, 0.8-1 mm wide, apices rounded, mucronate, mucros to about 0.1 mm; anthers 0.4-0.6 mm. Caryopses 0.8-1.2 mm. 2n = 14(18).
(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_reptans )