Abstract
Diterpenes from the Dictyoteae tribe appear to be valuable taxonomic markers and have showed, for various species, strong correlation with morphological data. Dictyota crispata Lamouroux is close to D. cervicornis Kützing. Crude extract of Brazilian D. crispata was analysed and compared by analytical TLC and NMR data with both the crude extract and the most abundant diterpenes of D. cervicornis. The results showed that D. crispata produces the same diterpenes as D. cervicornis, and thus the two species cannot be separated by chemotaxonomic studies. Our results indicate that the divergence time between these two species is small.
