harena, arena, = sand, sands, a sandy place, a sandy desert;
-astrum, = indicates inferiority or incomplete resemblance, hence often applied to the wild equivalent of a cultivated plant.
(Alien) (ld, BL, Cw)
undo, = to rise in waves or surges, to throw up waves, to surge, swell; to wave, undulate;
-ulus, = diminutive;
-atus, = indicates possession or likeness.
undulatus, = diversified as with waves, undulated.
(undulated) (ld, BL)