Systematics of the Neotropical Blueberry Genus Disterigma (Ericaceae)

Abstract

Disterigma s. l. comprises 37 species of small shrubs found in Central and South America, mostly in cloud forests and páramos. The notion that the morphological circumscription of Disterigma s. l. is too wide and that it may not be a monophyletic group was supported by recent molecular evidence extracted from only a few species of Disterigma. This study addresses the monophyly and position of Disterigma s. l. within the complex blueberry tribe Vaccinieae through an intensive taxon sampling. Seventy-nine species are sampled, including 84% of the species of Disterigma s. l. and 13 genera of neotropical Vaccinieae. The parsimony analysis of nrITS and ndhF data reveal that Disterigma s. l. is polyphyletic with three independent origins within Vaccinieae. The majority of the species form a well supported monophyletic group, Disterigma s. s., which is located within a large Andean clade; all Disterigma s. s. species share the presence of a differentiated pair of apical bracteoles. Segregated from Disterigma s. s., but also Andean in origin, is the novel Central Andes Segregated Disterigma clade, where D. bracteatum, D. pentandrum, D. rimbachii, and D. ulei are found. Also resolved outside of Disterigma s. s. is D. trimerum, a taxon of Mesoamerican origin.

Tropical and Temperate: Evolutionary History of Páramo Flora

“…Nuclear and plastid markers indicate that Disterigma is polyphyletic (Pedraza-Peñalosa, 2009). The six sampled páramo species occur in a well-supported Disterigma s.s. clade to which neotropical montane forest Sphyrospermum and central Andean Disterigma species are sister.…”

“…Based on the evidence, it may be concluded that Disterigma entered páramo from cloud forest. The poor resolution within the Disterigma s.s. clade, however, does not allow inference as to the number of colonization events (Pedraza-Peñalosa, 2009). Nevertheless, classification of Disterigma in the neotropical element is justified by molecular data.…”

New blueberry and mortiño relatives (Ericaceae) from northwestern Colombia

“…The taxonomic placement of new Vaccinieae is difficult due to the striking disparity between generic-level phylogenetic relationships and current classification systems (Kron et al 2002, Powell and Kron 2003, Pedraza-Peñalosa 2009, 2010). Therefore, to determine the generic placement of the new species, four were included in a comprehensive phylogenetic analysis of neotropical Vaccinieae, based on chloroplast and nuclear sequence data of 91 species (Pedraza-Peñalosa et al 2015).…”

Themistoclesia diazii, una nueva especie relacionada con los mortiños Colombianos (Ericaceae: Vaccinieae)1

“…En general, en la determinación de especies nuevas de Ericaceae el autor emplea el concepto filogenético de especie (Nixon & Wheeler 1990). En el caso de la especie acá descrita, la cual sólo se conoce por un individuo, se debe entender que este individuo es diagnosticable por una combinación única de caracteres y se asume que, en ausencia de más material, representa la variación de la especie.…”