The genus Evolvulus (Convolvulaceae) in the state of Pernambuco, Brazil

Abstract

The genus Evolvulus comprises species distributed throughout Americas, with two pantropical, E. nummularius and E. alsinoides. Currently in Brazil there are 73 species cataloged, most of them widespread, with Cerrado and Caatinga as the main diversity centers. This study aimed to carry out a taxonomic treatment of Evolvulus in the Brazilian state of Pernambuco. There were conducted 17 field expeditions and analysed 512 specimens from 26 herbaria. The diversity of the genus is contemplated by 17 species in Pernambuco, most of them widely distibuted in Brazil, except for E. daphnoides and E. saxatilis, which are endemic to Caatinga domain. E. filipes and Evolvulus glomeratus stands out as the most common species, present in all physiographic zones. Evolvulus elaegnifolius, E.sericeus and E. tenuis shows a disjoint distribution between the Atlantic forest and “Sertão” (backwoods). Most species are associated with hyperxerophytic Caatinga on sandy soils, in the physiographic zone of the “Sertão”, except E. nummularius that is restricted to the Atlantic forest, associated with podzolic soils. Evolvulus glomeratus also occurs on rocky outcrops, while E. saxatilis and E. saxifrages are restricted to this habit throughout the state. We present here an identification key, morphological descriptions, geographic distribution, ecological and taxonomic comments, and illustations.

Key words:
biodiversity; Caatinga; Brazilian flora; Solanales; taxonomy