A new Angolan species from the Triaspis hypericoides complex (Malpighiaceae) based on macromorphology and palynology

Abstract

Triaspis hypericoides currently comprises three accepted subspecies endemic to woodland savannas of southern continental Africa. After an unusual population belonging to this complex was collected in southwestern Angola, we re‐evaluated the classification of this group. This study was based on the analysis of type specimens, protologues, field photographs and herbarium sheets of all subspecies within T. hypericoides. We reinstate T. canescens, T. hypericoides and T. nelsonii based on differences in leaf, flower and fruit traits. Additionally, the Angolan population is proposed here as a new species of Triapis endemic to the dry miombo woodlands of Bicuar National Park, Huíla Province, southwestern Angola. Triaspis bicuarensis sp. nov. is easily distinguished from T. nelsonii by its alternate (versus opposite) leaves, ovate to widely ovate (versus widely ovate to very widely ovate) leaf laminas, rounded (versus sagittate) leaf base, flat (versus undulate) margins, sparsely white‐tomentose (versus glabrous to glabrescent) abaxial leaf surface, petiole 4–8 mm long (versus 2–3 mm long), compound inflorescences in thyrses (versus corymbs) and bracteoles inserted below apex of peduncles (versus in the middle of peduncles). An identification key to all species belonging to this species complex is presented alongside a complete morphological description for the new species, photographic plates and comments on the distribution, ecology, palynology and taxonomy. These results underline the need for continued revisions of the taxonomy of the neglected African genera of Malpighiaceae.

A new classification system and taxonomic synopsis for Malpighiaceae (Malpighiales, Rosids) based on molecular phylogenetics, morphology, palynology, and chemistry

“…material 1 ) endemic to rainforests, savannas, and seasonally dry tropical forests of Angola, Benin, Botswana, Cameroon, Cape Green, Congo, Ethiopia, Gabon, Ghana, Guinea, Ivory Coast, Kenya, Liberia, Malawi, Mozambique, Namibia, Nigeria, Sierra Leone, Somalia, South Africa, Tanzania, Togo, Zambia, Zaire, and Zimbabwe, Africa ( POWO 2024 ). There is no current identification key for all species of Triaspis , but for regional keys, see Niedenzu (1928) , Launert (1968) for East Africa, Badré (1972) for Cameroon, Badré (1973) for Gabon, Hutchinson and Dalziel (1958) for West Tropical Africa, Wilczek (1958) for Democratic Republic of Congo, and Almeida et al (2024) for Southern Africa.…”

“…Chromosome numbers were retrieved from Anderson (1993) and Lombello and Forni-Martins (2002 , 2003 ), and secondary metabolites were retrieved from Mannochio-Russo et al (2022) . Palynological data were retrieved from Lowrie (1982) , Silva et al (2023) , and Almeida et al (2024) and complemented by the slide collections from the Instituto de Pesquisas Ambientais (São Paulo, Brazil) and the Royal Botanic Gardens, Kew.…”