Open AccessThree new species of Tricalysia (Rubiaceae) from Atlantic Central Africa
Author(s) -
Olivier Lachenaud,
Tariq Stévart,
Bonaventure Sonké
Publication year - 2020
Publication title -
plant ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.422
H-Index - 23
eISSN - 2032-3921
pISSN - 2032-3913
DOI - 10.5091/plecevo.2020.1670
Subject(s) - iucn red list , herbarium , conservation status , rubiaceae , threatened species , iucn protected area categories , calyx , endangered species , data deficient , biology , near threatened species , critically endangered , taxonomy (biology) , botany , endemism , geography , ecology , habitat
Background and aims – The genus Tricalysia A.Rich. (Rubiaceae), regarded here in the strict sense (i.e., excluding Empogona Hook.f.), includes 77 species in tropical Africa, Madagascar and the Comoros. In the current paper, three new species from Atlantic Central Africa are described and illustrated; their conservation status is also assessed.Material and methods – This paper is based on a study of herbarium collections from BR, BRLU, K, LBV, P, WAG and YA. Normal practices of herbarium taxonomy have been applied. The conservation status assessments follow the IUCN Red List criteria.Results – Tricalysia lophocarpa O.Lachenaud & Sonké is endemic to Gabon and is best recognised by its fruits with 8–10 narrow longitudinal ribs. Tricalysia obovata O.Lachenaud & Sonké is endemic to Equatorial Guinea (Rio Muni) and may be recognised by its obovate leaves with rounded base, glabrous stems, and sessile flowers with included style and half-exserted anthers. Tricalysia wilksii O.Lachenaud & Sonké occurs in Gabon and southwestern Republic of Congo, and may be recognised by its glabrous stems and leaves, the latter with crypt domatia, its linear calyx teeth equalling or exceeding the tube in length, and its shortly pedicellate fruits. The three species are assessed respectively as Near-threatened (T. lophocarpa), Critically Endangered (T. obovata) and Vulnerable (T. wilksii).