Lewis & Short

scirpus (sometimes sirpus), i, m.

  1. I. A rush, bulrush, Plin. 16, 37, 70, § 178; 7, 56, 57, § 206; Fest. p. 330 Müll.; Plaut. Rud. 2, 6, 39; Vulg. Job, 8, 11.
        1. b. Prov.: nodum in scirpo quaerere, to seek a knot in a bulrush, to find a difficulty where there is none: quaerunt in scirpo, soliti quod dicere, nodum, Enn. ap. Fest. p. 330 (Sat. v. 46 Vahl.); so, in scirpo nodum quaeris, Plaut. Men. 2, 1, 22; and: no dum in scirpo quaeris, Ter. And. 5, 4, 38.
  2. II. Transf., deriving the idea of intricacy from plaited work of rushes, a riddle, enigma: quae Graeci dicunt aenigmata, hoc genus quidam e nostris veteribus scirpos appellaverunt, Gell. 12, 6, 1.