Boyd’s Bible Dictionary:
(fluttering). Embraces many water plants (Ex. 2:3-5; Isa. 19:6).
Concise Bible Dictionary:
1. achu, a soft reed that can only grow in moist ground: it is eaten by cattle (Job 8:11).
2. suph, a weed that grows on the banks of the Nile, among which Moses in the ark was laid (Ex. 2:3, 5; Isa. 19:6).
Cyperus Papyrus—Reeds that Grow Along the Nile
Cyperus Papyrus