A taxonomic revision of the genus Tamonea (Verbenaceae)

Abstract

A taxonomic revision of the genus Tamonea is provided. Tamonea is a small genus of Verbenaceae, placed in the tribe Casselieae. It is represented by six species, distributed in tropical and temperate America, from Mexico and the Caribbean in the north, to Brazil, Paraguay and Bolivia in the south. Four new combinations are introduced: Tamonea curassavica var. australis, T. curassavica var. cardenasii, T. curassavica var. parvifolia and T. curassavica var. yucatanensis; a new synonym is proposed for T. curassavica var. curassavica. The species Tamonea juncea is lectotypified. Detailed morphological descriptions are given for each taxon, in addition to a key for their identification, illustrations, actualized synonymy, distribution and specimens lists, as well as discussion about the relationship between closely related taxa.

The Catalogue of Vascular Plants of the Southern Cone and the Flora of Argentina: their contribution to the World Flora

“…There are several possible causes to explain this variation: description of new taxa, record of new occurrences for the area or adjustment of taxonomic circumscription at all levels, often as a result of new taxonomic and phylogenetic research. Therefore the species number accepted within a certain genus may decrease when new synonymies are proposed, as seen in genus Phyla L. (O'Leary & Múlgura 2012) or it may increase through the description of new species, as was the case with Chusquea Kunth, through the description of Chusquea egluma Guerreiro & Rúgolo and Chusquea floribunda Guerreiro & Rúgolo in 2013(Guerreiro & Rúgolo de Agrasar 2013. The number of genera may increase through segregation of a group of species to another genus, as seen in 2014 for Panicum validum Mez that was split from Panicum L. and placed within the new genus Osvaldoa J.R. Grande (Grande Allende 2014), causing an increase in the number of genera in the Poaceae.…”

The Phylogeny and Biogeography of Phyla nodiflora (Verbenaceae) Reveals Native and Invasive Lineages throughout the World

“…O'Leary and Múlgura [7] do not cite the monograph by Kennedy [6]. However, it would appear that Kennedy [6] and O'Leary and Múlgura [7] also differ in the circumscription of species limits as the same specimens from southern South America are allocated to different species by them (e.g., MacBride 5880, US, is recognised as P. canescens [6] or P. nodiflora var nodiflora [7]). …”

“…The taxa outside of Australia with the closest native range to P. nodiflora include the Latin American P. canescens, P. betulifolia (Kunth) Greene and P. fructicosa (= P. nodiflora var. reptans (Kunth) Moldenke, [7]) but none of these taxa is native to Australia's near neighbours of New Guinea, Timor, Java or New Zealand. For Criterion 8 (Table 1) several islands in Asia (e.g., Guam) hold alien populations of P. nodiflora and are potential source areas for distribution into Australia.…”

“…It was considered to be a separate species from P. canescens (Kunthe) Greene in taxonomic revisions by Kennedy [6] and Munir [8], but most recently O'Leary and Múlgura [7] made a new combination and listed these taxa as varieties of P. nodiflora (P. nodiflora var. nodiflora and P. nodiflora var.…”

“…Phyla nodiflora (L.) Greene (Verbenaceae), a perennial mat-forming herb in neotropical Phyla (Verbenaceae), is a cryptogenic species. In the Americas P. nodiflora occurs from lower North America (including Florida) to northern South America [6] with a disjunct occurrence in Brazil [6,7]. In Australia, P. nodiflora occurs in tropical and sub-tropical regions with several disjunct temperate occurrences [8].…”