A revision of the endemic Brazilian Solanum hexandrum group (Leptostemonum, Solanum, Solanaceae)

By

Knapp, Sandra
Gouvêa, Yuri
Giacomin, Leandro Lacerda

Type

Article

Date of Publication

2025-3-12

Original Publication

PhytoKeys

Volume

253

Pages

199--259

Subjects

Atlantic forest , Brazil , endemism , fruit morphology , prickles

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers [2010]-

Identifiers

DOI: https://doi.org/10.3897/phytokeys.253.138216

 

Abstract

The Leptostemonum Clade, or the ‘spiny solanums’, represents half of the species diversity of the large cosmopolitan genus Solanum (Solanaceae). Brazil is a centre of both species and lineage diversity in ‘spiny solanums’ with a number of lineages occurring mostly only there. Here, we treat the Solanum hexandrum group, a monophyletic species group that is part of the larger and unresolved Erythrotrichum clade sensu lato. The six species treated here are all robust very prickly shrubs with amongst the largest and showiest flowers in Solanum and accrescent calyces in fruit that often completely cover the mature berry. All six species are endemic to the coastal Atlantic forests of south-eastern and north-eastern Brazil. We describe one new species, S. phrixothrix Gouvêa & S.Knapp, sp. nov., known only from two collections made 200 years apart. Many of the species in the group occur in very small populations around isolated gneissic/granitic inselbergs, a highly threatened habitat in the region. We provide complete nomenclatural details for all recognised species and their synonyms, complete descriptions, distributions including maps, illustrations, common names and uses and preliminary conservation assessments.