It is a delicate, profusely branched alga that is greenish to pinkish or light red in color. The branching of Jania ungulata is dichotomous in one plane, with pinnate branching in subsidiary axes. This means that the alga branches in two at each point, with the secondary branches branching off in a feather-like pattern. The terminal branchlets of Jania ungulata are terete or slightly flattened, forked or unbranched, and often tapering distally. Terete means cylindrical, and flattened means that the branchlets are wider than they are thick. The intergenicula of Jania ungulata are cylindrical. Intergenicula are the segments of the alga that lie between the nodes, which are the points where the branches join the main axis.They are often surrounded by lateral branchlets.