Lewis & Short

sarmentum, i, n. [sarpo], twigs, light branches, brushwood; a fagot, fascine (class.; usu. in plur.; only so in Cic. and Cæs.; cf.: lignum, materia); sing., Varr. R. R. 1, 31, 2; Col. 3, 10, 1; Sil. 7, 314.
Plur., Col. 4, 24, 7; 5, 5, 16; Cic. Sen. 15, 52 and 53; id. de Or. 2, 21, 88; id. Verr. 2, 1, 27, § 69; * Caes. B. G. 3, 18 fin.; Liv. 22, 16 fin.; Quint. 2, 17, 19; Plin. 12, 25, 54, § 118; 22, 25, 72, § 150 al.