Redefinition of Stachytarpheta sprucei (Verbenaceae) reveals a remarkable geographic disjunction in tropical forests of South America

CARDOSO, P. E.; O'LEARY, NATALY; MENINI NETO, L.; TROVÓ, M.

ACTA BOTANICA BRASILICA

SOC BOTANICA BRASIL

Lugar: San Pablo; Año: 2023 vol. 37 p. 1 - 8

0102-3306

Stachytarpheta is the second largest genus of Verbenaceae, mainly distributed in xeric habitats of South America. Themorphological revision of South American specimens clarified the taxonomic identity of three previously acceptedspecies from informal group Gesnerioides: S. sprucei (from the Amazon Forest domain), S. alata, and S. tomentosa (fromthe Atlantic Forest domain). A new taxonomic arrangement is proposed here, with the synonymization of S. alata andS. tomentosa under S. sprucei. Consequently, the newly circumscribed S. sprucei evidences a remarkable geographicdisjunction, with populations separated by the Caatinga, Cerrado, and Chaco domains (the South American drydiagonal). It inhabits inselbergs, tepuis, and savannas in the Amazon Forest domain, and top of inselbergs surroundedby forest in the Atlantic Forest domain. A detailed species description, taxonomic comments, a geographic distributionmap, photos of living specimens, and an identification key to the species from the Gesnerioides group are included.