New records and lectotypifications in Richardia (Rubiaceae) for the flora of the Southern Cone of South America. NUEVOS REGISTROS Y LECTOTIPIFICACIONES EN RICHARDIA (RUBIACEAE) PARA LA FLORA DEL CONO SUR DE SUDAMÉRICA

MIGUEL, LAILA M.; CHEQUIN, RENATA NICORA; CABRAL, ELSA L.; SALAS, ROBERTO M.

DARWINIANA

INSTITUTO DE BOTÁNICA DARWINION

Año: 2022 vol. 10 p. 251 - 259

0011-6793

Richardia is a Neotropical genus, belonging to tribe Spermacoceae, family Rubiaceae. It comprises 16 species distributed from the southeastern United States to Argentina and Uruguay. As part of the studies of the genus for the flora of the Southern Cone of South America, and particularly as a contribution to the Argentinean flora, we present here the results of the taxonomic studies obtained in this genus. The botanical collections available in both national and foreign herbaria, digitalized collections in online databases and specific literature were reviewed. As a result, two new records are presented, Richardia pedicellata for Misiones province, and R. scabra var. chacoensis for Salta, with their respective illustrations and a distribution map. In addition, lectotypes are designated for three accepted species: R. humistrata, R. pedicellata, and R. stellaris, and for the following synonyms: Richardsonia acutifolia, R. divergens, R. emetica, R. rosea, and R. sparsa. An updated key to the Richardia species of Argentina is also presented.