Growth rates and the ability to date an organism can greatly contribute to understanding its population biology and community dynamics. 1n 1954, V. N. Andreev proposed a method to date regularly branched members of Cladonia, a fruticose lichen, using total thallus length and number of internodes. No research, however, has demonstrated the reliability of this technique or compared its estimates to those derived by other means. In this study, we demonstrate the utility of 14C/C ratios to determine lichen age and growth rate in Cladonia stygia (Fr.) Ruoss collected from north-western Alaska, USA. The average growth rate using 14C/C ratios was 6·5 mm yr−1, which was not significantly different from growth rates derived by Andreev's internode method (average = 6·2 mm yr−1); thus, suggesting the reliability of Andreev's simple field method for dating lichens.