Aguirre-Santoro 2017 (Article) Ronnbergia, Wittmackia
Taxonomy of the Ronnbergia Alliance (Bromeliaceae: Bromelioideae): new combinations, synopsis, and new circumscriptions of Ronnbergia and the resurrected genus
Author(s):—J. Aguirre-Santoro
Publication:—Plant Systematics and Evolution 303(online): 1-26. (2017) — DOI
Abstract:—The Ronnbergia Alliance is a recently described lineage composed of two highly supported and identifiable clades with strong geographic correlation: the Pacific and the Atlantic clades. These clades, however, are composed by species currently placed in the polyphyletic genera Aechmea, Hohenbergia, and Ronnbergia. This study aims to reorganize the species that comprise both the Pacific and Atlantic clades into stable and predictable taxonomic categories. In this context, the 26 species that compose the Pacific clade are here circumscribed in the genus Ronnbergia, whereas the 44 species grouped in the Atlantic clade are assigned to the resurrected genus Wittmackia. An updated circumscription of these two genera is presented, including a taxonomic key to recognize the species. Additionally, the respective taxonomic transferences and general information to the species are presented in the form of a synopsis. This taxonomic treatment will facilitate future approaches on the study of the systematics, conservation, and evolution of the Ronnbergia Alliance.
Keywords:—Atlantic Forest , Caribbean, ChocoŽ-DarieŽn region, Ronnbergia, Wittmackia
Published names (54):Taxonomy:—Aechmea patentissima See resurrection of Wittmackia (p.22).—Aechmea wittmackiana Recognized as Wittmackia .—Hohenbergia brittoniana Considered synonym to Wittmackia distans (Griseb.) Aguirre-Santoro (p.19).—Hohenbergia gnetacea Hohenbergia gnetacea is synonymized here under Wittmackia polycephala because the type of the former exhibits the following diagnostic characters for W. polycephala: sessile, subglobose spikes surpassed by the primary bracts, and floral bracts covered with brown-tomentose- lepidote indument. Smith (1960) had already suggested that the type specimen of H. gnetacea was doubtfully different from W. polycephala but did not propose its synonymy because this specimen lacks leaves, the inflorescence is exceptionally lax, and it does not have locality information. The study of intraspecific variation in W. polycephala in the present work revealed that lax inflorescences are common in W. polycephala, thus discarding this character as diagnostic for H. gnetacea. Moreover, the leaf architecture among the species of Caribbean Wittmackia is rarely used to differentiate species within the group; for this reason, it is safe to suggest that the lack of this character may not have a large impact in the proposal of the present synonymy. Although it is impossible to know the original locality of the type specimen of H. gnetacea, its strobiliform spikes and unappendaged ovules allow its placement within Caribbean Wittmackia. (p.23).—Hohenbergia proctorii Hohenbergia proctorii is synonymized here to W. urbaniana based on the remarkable similarity of its type collection with fruiting individuals of W. urbaniana, and the overlap in the diagnostic characters. The main diagnostic character used to separate H. proctori from W. urbaniana is the acuminate and inconspicuous wing of the posterior sepals in the former (vs. obtuse); however, this ambiguous character was found to be variable in flowering and fructifying specimens of W. urbaniana, and it is not particularly distinctive in the type of H. proctori. Another justification for this synonymization is that the type locality of H. proctori overlaps with the distribution range of W. urbaniana. (p.25).—Wittmackia Resurrection, recircumscription, and synopsis (p.16).—Wittmackia lingulata Recognized as Wittmackia .—Wittmackia patentissima Resurrected in Wittmackia (p.22).—Wittmackiopsis (subgen. of Hohenbergia) Considered synonymous to Wittmackia Mez (p.16).