Abstract: This paper studied the seasonal dynamics of the growth and distribution of freshwater rhodophyte Batrachospermum gelatinosum in Niangziguan of Pingding County,Shanxi Province,North China,from September 1992 to June 1994.The water temperature,pH,current velocity,occurrence frequency,mean cover,plant height,whorl diameter,fascicle length,carpogonial branch length,carpogonium length,carpogonial diameter,carposporophyte number per whorl,carposporophyte diameter,carposporangium length and carposporangium diameter were examined regularly.The results showed that water temperature was the maximum in July and minimum in January,water pH had little change,and the variation of current velocity was irregular.The occurrence frequency and mean cover of the alga were increased from Autumn to Spring,and the highest were in May.The seasonal growth dynamics of this alga were evident.It developed well from late Autumn to early Summer,and peaked in May.It was positively correlated to each other among morphological characteristics,and the development was synchronal in all parts of the plant.

Key words: Freshwater red algae, Batrachospermum gelatinosum, Seasonal dynamics, Niangziguan spring