Polysiphonia are plant-like organisms that are predominantly found in marine environments and are more commonly known as red algae. Although a few species may be found in freshwater, red algae are typically attached to rocks or other plants in tropical and subtropical deep waters or washed along shorelines. These algae manifest many shapes and close observation reveals filaments, branches, feathers, or sheet-like structures (the scientific name for red algae is derived from Greek words meaning "many pipes"). Red algae are hardy and even tiny fragments are able to survive winter cold or harsh environments by remaining dormant until more favorable conditions encourage them to grow. The reproductive cells of red algae are not equipped to move on their own and fertilization occurs only when male spermatium are carried by water currents to a receptacle on the female reproductive organ.