Key to the common species of Gelidium
| 1 | Plants up to 20 cm high, axes like a plume at top, smooth or slightly toothlike below; occurring in areas of strong water motion | G. pluma Loomis |
| 1 | Plants with axes and branches cylindrical to compressed, mostly irregularly pinnately branched; no more than 4 cm high, commonly forming mats on seaward facing rocks | G. pusillum (Stackhouse)Le Jolis |
Back to Common Hawaiian Red Algal Genera