Species delimitation in Lippia section Goniostachyum (Verbenaceae) using the Phylogenetic Species Concept

O'LEARY, NATALY; DENHAM SILVIA; SALIMENA FATIMA; MÚLGURA MARÍA EMA

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012 vol. 170 p. 197 - 219

0024-4074

Lippia section Goniostachyum comprises plants distinguished by its numerous axillary florescences (3-6, sometimes up to 9) and floral bracts tetrastically arranged. Species of section Goniostachyum range in the Neotropics, from Mexico to Northern Argentina. Delimitation of the species grouped under Goniostachyum has remained unclear. Forty one names exist under this section, but only ca. 8-10 names have been frequently used. To resolve the taxonomy of this group a modified Population Aggregation Analysis, based on phylogenetic species concept, was employed. As a result Goniostachyum is here circumscribed to only four species, L. grata, L. origanoides, L. sericeae and L. stachyoides. These species are sustained by a different combination of three characters, out of the 13 qualitative attributes analyzed: canescent sericeous pubescence, frondose or frondose-bracteose inflorescences and free or fused florescence apical bracts. Two varieties based on significant differences among quantitative characters are recognized: L. stachyoides var. stachyoides and L. stachyoides var. martiana, nov. comb. Fifteen lectotypifications and 3 neotypifications are here proposed.