Phenology ofLemanea fucina (Rhodophyta) in a Rhode Island river,USA

In a fourth-order river in Rhode Island, USA, cover, frequency of occurrence, length and node number of the red algaLemanea fucina were greatest in July and August, at which time current velocity and water depth were minimum and temperature was maximum. Population abundance and plant size were lowest in fall-early winter. The length of reproductive region and carpospore frequency were also highest in June to August, whereas percent plants with open tips was least in July and highest in February. It appears that growth and reproduction are confined to a period from April to August, after which there is thallus deterioration and carpospore release; between September and March remnants of this population remain.Lemanea plants are epiphyte-free from September to January. Subsequently, they are colonized by caddisflies and then the red algaAudouinella violacea; by August, 100% of theLemanea plants are covered byAudouinella.