glaucus

noun2

1. •
   Any member of the genus Glaucus of nudibranchiate mollusks, found in the warmer latitudes, swimming in the open sea, strikingly colored with blue and silvery white.
2. •
   A desert lime (Citrus glauca), a thorny shrub species endemic to semi-arid regions of Australia.

   • This pass is extremely abrupt, and is covered with glaucus, the low scrub I have noticed as common to the sand-stone formation. — 1833