Discovering Karima (Euphorbiaceae), a New Crotonoid Genus from West Tropical Africa Long Hidden within Croton

Martin Cheek; Gill Challen; Aiah Lebbie; Hannah Banks; Patricia Barberá; Ricarda Riina

doi:10.1371/journal.pone.0152110

Discovering Karima (Euphorbiaceae), a New Crotonoid Genus from West Tropical Africa Long Hidden within Croton

PLoS One. 2016 Apr 6;11(4):e0152110. doi: 10.1371/journal.pone.0152110. eCollection 2016.

Authors

Martin Cheek¹, Gill Challen¹, Aiah Lebbie², Hannah Banks¹, Patricia Barberá³, Ricarda Riina³

Affiliations

¹ Science Department, Royal Botanic Gardens, Kew, Surrey, United Kingdom.
² National Herbarium of Sierra Leone, Dept. of Biological Sciences, Njala University, PMB, Freetown, Sierra Leone.
³ Department of Biodiversity and Conservation, Real Jardín Botánico, RJB-CSIC, Plaza de Murillo, Madrid, Spain.

Abstract

Croton scarciesii (Euphorbiaceae-Crotonoideae), a rheophytic shrub from West Africa, is shown to have been misplaced in Croton for 120 years, having none of the diagnostic characters of that genus, but rather a set of characters present in no known genus of the family. Pollen analysis shows that the new genus Karima belongs to the inaperturate crotonoid group. Analysis of a concatenated molecular dataset combining trnL-F and rbcL sequences positioned Karima as sister to Neoholstia from south eastern tropical Africa in a well-supported clade comprised of genera of subtribes Grosserineae and Neoboutonieae of the inaperturate crotonoid genera. Several morphological characters support the relationship of Karima with Neoholstia, yet separation is merited by numerous characters usually associated with generic rank in Euphorbiaceae. Quantitative ecological data and a conservation assessment supplement illustrations and descriptions of the taxon.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Africa, Western
Euphorbiaceae / classification
Euphorbiaceae / genetics*
Genes, Plant*
Microscopy, Electron, Scanning
Phylogeny
Pollen / ultrastructure

Grants and funding

The fieldwork which produced the specimen which triggered this study was ultimately funded by Joule Engineering as part of baseline studies for a hydroelectric dam at Bumbuna-Yiben, Sierra Leone. The funder of the fieldwork had no role in study design, data-collection and analysis, decision to publish or preparation of the manuscript. RR visit to WAG was supported by the EU program Synthesys (NL-TAF-3710). PB was supported by the Spanish Government through projects: Flora de Guinea Ecuatorial (CGL2012–32934) and Flora Iberica (CGL2014-52787-C3-1-P).