Elatostema J.R.Forst. & G.Forst. (Urticaceae) is a taxonomically problematic genus of approximately 300 species that is widespread throughout the tropical, subtropical and sub-temperate regions of Africa through to SE Asia, Australasia to Polynesia. Morphological and molecular analyses were conducted to evaluate the infra-familial classification of the Urticaceae, to test the monophyly of Tribe Elatostemeae, to define generic limits of Elatostema and assess its relationship within the tribe, and to examine the current infrageneric grouping within Elatostema. Phylogenetic analyses based on choloroplast DNA sequences of rbcL and trnL-F do not provide support for the monophyly of Urticaceae, because of the position of Poikilospermum (currently Cecropiaceae) within the tribe Urticeae. Although the status of Cecropiaceae is equivocal, there is support for the inclusion of this family in the Urticaceae, with Cecropia and Coussapoa (Cecropiaceae) having close affinities to the Boehmerieae and Parietarieae. The phylogenetic position of Myriocarpa is unresolved, but is excluded from the Boehmerieae, as currently classified. The Elatostemeae is paraphyletic with Pilea placed sister to the Urticeae. Evaluation of the infrageneric classification of Elatostema, based on phylogenetic analyses of both morphological and molecular data (trn and ITS) does not support the current subgeneric classification as proposed by Schr??ter and Winkler (1935, 1936). The analyses support two main infrageneric grouping: (1) a group consisting of Elatostema subg. Pellionia and Procris, and (2) a group consisting of the remaining members of Elatostema (including E. griffithianum ??? subg. Pellionia). The molecular data are regarded as a more accurate estimate of the phylogeny than provided by morphology, with molecular data having a higher Rescaled Consistency Index on the most parsimonious trees, together with a much greater level of resolution and support than that of the morphological analyses.

Elatostema J.R.Forst. & G.Forst. (Urticaceae) is a taxonomically problematic genus of approximately 300 species that is widespread throughout the tropical, subtropical and sub-temperate regions of Africa through to SE Asia, Australasia to Polynesia. Morphological and molecular analyses were conducted to evaluate the infra-familial classification of the Urticaceae, to test the monophyly of Tribe Elatostemeae, to define generic limits of Elatostema and assess its relationship within the tribe, and to examine the current infrageneric grouping within Elatostema. Phylogenetic analyses based on choloroplast DNA sequences of rbcL and trnL-F do not provide support for the monophyly of Urticaceae, because of the position of Poikilospermum (currently Cecropiaceae) within the tribe Urticeae. Although the status of Cecropiaceae is equivocal, there is support for the inclusion of this family in the Urticaceae, with Cecropia and Coussapoa (Cecropiaceae) having close affinities to the Boehmerieae and Parietarieae. The phylogenetic position of Myriocarpa is unresolved, but is excluded from the Boehmerieae, as currently classified. The Elatostemeae is paraphyletic with Pilea placed sister to the Urticeae. Evaluation of the infrageneric classification of Elatostema, based on phylogenetic analyses of both morphological and molecular data (trn and ITS) does not support the current subgeneric classification as proposed by Schr??ter and Winkler (1935, 1936). The analyses support two main infrageneric grouping: (1) a group consisting of Elatostema subg. Pellionia and Procris, and (2) a group consisting of the remaining members of Elatostema (including E. griffithianum ??? subg. Pellionia). The molecular data are regarded as a more accurate estimate of the phylogeny than provided by morphology, with molecular data having a higher Rescaled Consistency Index on the most parsimonious trees, together with a much greater level of resolution and support than that of the morphological analyses.