| Polysiphonia atlantica Kapraun & J.N. Norris, 1982 |
| Polysiphonia bajacali Hollenberg, 1961 |
| Polysiphonia beaudettei Hollenberg, 1961 |
| Polysiphonia bifurcata Hollenberg, 1945 |
| Polysiphonia binneyi Harv., 1853 |
| Polysiphonia boldii Wynne & P. Edwards, 1970 |
| Polysiphonia breviarticulata (C. Agardh) Zanardini, 1840 |
| Polysiphonia breviarticulata var. breviarticulata (C. Agardh) Zanardini, 1840 |
| Polysiphonia breviarticulata var. mexicana Kütz., 1863 |
| Polysiphonia brodiei (Dillwyn) Spreng., 1827 |
| Polysiphonia californica Harv., 1853 |
| Polysiphonia concinna Hollenberg, 1944 |
| Polysiphonia confusa Hollenberg, 1961 |
| Polysiphonia cuspidata J. Agardh, 1847 |
| Polysiphonia decussata Hollenberg, 1942 |
| Polysiphonia denudata (Dillwyn) Grev. ex Harv., 1833 |
| Polysiphonia determinata (Hollenberg) Savoie & G.W. Saunders, 2019 |
| Polysiphonia eastwoodiae Setch. & N.L. Gardner, 1930 |
| Polysiphonia echinata Harv., 1853 |
| Polysiphonia exilis Harv., 1853 |