The plants are composed of soft and single layer tubular filaments with several constrictions in the middle to upper portions. The branchlets are few in number, and arise from only lower parts of the plant. The diameter of the main axes is wider in the upper portions and narrower in the lower portions. This species is green to dark green in color, and found on rocks or other substrates in middle to lower intertidal zones along calm to moderate wave exposed shorelines.

References: http://www.jircas.affrc.go.jp/project/aquacult_Thailand/data/ulva_compressa.html