Monadelpha (Euphorbiaceae, Plukenetieae), a new genus of Tragiinae from the Amazon rainforest of Venezuela and Brazil

• Main Authors: Lynn J. Gillespie, Warren M. Cardinal-McTeague, Kenneth J. Wurdack
• Format: Article
• Language: English
• Published: Pensoft Publishers 2020-12-01
• Series: PhytoKeys
• Online Access: https://phytokeys.pensoft.net/article/59244/download/pdf/

Monadelpha L.J.Gillespie & Card.-McTeag., gen. nov., is described as a new member of Euphorbiaceae tribe Plukenetieae subtribe Tragiinae, to accommodate Tragia guayanensis, a species known from western Amazonas, Venezuela and, newly reported here, from Amazonas, Brazil. The genus is unique in the subtribe for having 5-colpate pollen and staminate flowers with filaments entirely connate into an elongate, cylindrical staminal column terminated by a tight cluster of anthers. Phylogenetic analyses based on nuclear rDNA ITS and sampling 156 accessions across the diversity of Tragiinae (all 12 genera and 77 of ~195 species) also support Monadelpha as a distinct lineage that is separate from Tragia. A revised key to the genera of Tragiinae in South America and Central America is provided.