Seasonal dynamics of concentrations of soluble carbohydrates (sucrose, glucose, fructose, and their sum denoted as total non-structural carbohydrates, TotCarb) in rhizomes of Phragmites australis (common reed) and Typha latifolia (cattail) were monitored in an irrigation channel and at Lake Kumasir shores in Kahramanmaras, Turkey, during the vegetation period 2004-2005. The soluble carbohydrate concentrations of the rhizomes of Mug-mites australis and Typha latifolia were low at the beginning of the vegetation period; they reached their minima in February and March, respectively. Thereafter, soluble carbohydrate concentrations of both plants gradually increased until maximal values in August, thereafter decreasing gradually. Total soluble carbohydrate concentration in Typha latifolia rhizomes was higher than that of Phragmites australis during all months. Fructose prevailed in soluble carbohydrates throughout the season in Phragmites, followed by sucrose and glucose. In Typha latifolia the major sugar was glucose, followed by sucrose and fructose. (C) 2011 Elsevier GmbH. All rights reserved.