Notes on the genus Callitriche (Plantaginaceae, Callitricheae) in South America, and an identification key for Brazil

ABSTRACT

Callitriche is a genus of small herbs, ranging from aquatic to amphibious and terrestrial, the taxonomy of the genus is complicated and still unresolved, and knowledge of species distribution is still deficient. The present work aims to contribute to the taxonomic and geographical knowledge of Callitriche in South America by presenting the first records of C. terrestris subsp. subsessilis in the Brazilian states of Rio de Janeiro, Santa Catarina and Sergipe, and by presenting evidence that C. lechleri and C. stagnalis, which have been reported for Brazil in taxonomic databases, do not occur in this country. We also lectotypify C. lechleri, and present the first records of C. stagnalis in Chile and the Falkland Islands. Finally, we provide a key to the identification of the four species of Callitriche that occur in Brazil.

KEYWORDS:

• Callitriche lechleri
• Callitriche stagnalis
• Callitriche terrestris subsp. subsessilis
• distribution extension
• Lamiales
• new records
• typification

Acknowledgements

Thanks are due to Marta Cristina Vieira Farias (Universidade Federal de Sergipe) for supporting this study; to the curators and staff of all the herbaria cited in Material and Methods for receiving us during our studies, for the loan of herbarium specimens, for providing images of herbarium specimens and for providing important information to this study; and to anonymous reviewers for contributing to improve this paper. Gustavo Hassemer also acknowledges three SYNTHESYS grants for visits to K, MA and P herbaria (processes GB-TAF-5317, ES-TAF-6610 and FR-TAF-6529). Richard Lansdown acknowledges a grant (no. 15259235) from the Mohammed Bin Zayed Species Conservation Fund.