Polysiphonia brodiaei is a dark brownish purple algae growing as tufts consisting ofbranched of axial cellssurrounded by 6 - 8 periaxial cells all of the same length. These branches become corticated near the base. Trichoblasts form near the tip and branches develop from their axils. It grows to 36 cm long in dense tufts.
Reproduction
The plants are dioecious, Spermatangial branchlets are borne near the tips of the branches. Cystocarps with a wide ostiole develop and Tetrasporangiaappear as a spiral in the branches.