Vertebrata thuyoides is a small marine algae growing to 15 cm high in dense tufts of erect branches borne alternately and in one plane.

The erect branches have 8 to 10 pericentral cells surrounding the central axis and are all of the same length.

[2][1] Pterosiphonia complanata is similar but can be distinguished by having 5 pericentral around the central cells of the axes.

[1] Common in the British Isles on the southern coasts and Orkney.

Cystocarps are very small, sessile and borne on the branches.