The phloroglucinol composition of 29 species of Dryopteris Adanson belonging to subgenus Dryopteris section Marginatae were investigated on a world-wide basis, and the taxonomy is discussed based on both morphology and chemistry. The ferns of this section show relatively variable phloroglucinol patterns in line with their morphological variability. In good agreement with the other sections of subgenus Dryopteris, the majority of ferns of sect. Marginatae contain considerable amounts of phloroglucinols (crude filicin) and oleo-resin (ether extract) in their rhizomes and stipe-bases. However, D. porosa from China and the Hawai'ian species D. mauiensis were lacking in these phenolics. The African species, D. pentheri, D. lewalleana and D. manniana, are subdivided here into two separate chemical races, however, this does not affect their taxonomic identity, except in the case of D. manniana. Dryopteris wideniana Fraser-Jenk. is described as a new species in the D. manniana aggregate from S and E Africa.