Phylogenetic relationships within Tillandsia subgenus Diaphoranthema (Bromeliaceae, Tillandsioideae) based on a comprehensive morphological dataset

Abstract

Tillandsia subgenus Diaphoranthema (Tillandsioideae, Bromeliaceae) includes 29 epiphytic species distributed widely from southern North America to central Argentina and Chile. The species of Diaphoranthema are characterized by few small flowers, and most species are differentiated by phyllotaxy, leaf shape, flower number, and by the morphology and number of bracts. In addition to the highly variable vegetative characters, most species of subgenus Diaphoranthema possesses polyembryonic seeds (rare in Bromeliaceae) and an autogamous breeding system with a few number of species having cleistogamous flowers. In order to clarify relationships within Diaphoranthema and to understand the evolution of polyembryony, the breeding system, and diagnostic characters, a cladistic analysis of all known species using 85 morphological characters was conducted. Phylogenetic results suggest that Diaphoranthema is monophyletic if some species from the closely related subgenus Phytarrhiza are included. These two subgenera can only be distinguished from each other by the shape and size of their petals. A complete sampling of Phytarrhiza is still needed to test these hypotheses. None of the six informal groups as previously recognized are monophyletic. Vegetative characters such as phyllotaxy and the shape, length, and width of leaves were the most useful for distinguishing four major clades within Diaphoranthema. Flower number, scape development, exocarp and endocarp fusion at fruit ripening, and absence of endosperm in mature seeds were also used to distinguish some clades. Evolutionary trends favour a distichous phyllotaxy, linear shape leaf blades, and a reduction in flower number and bracts per inflorescence. In addition, capsules with disaggregating exocarp and endocarp at ripening, and polyembryonic seeds are also derived states within subgenus Diaphoranthema.

Novedades del género Tillandsia (Bromeliaceae, Tillandsioideae) para Uruguay

“…Para la identificación de las especies se consultó bibliografía de referencia (Castellanos, 1945;Smith, 1972;Smith & Downs, 1977;Castello & Galetto, 2013;Donadío et al, 2015), protólogos y ejemplares tipo. Adicionalmente, se compararon las muestras procedentes de Uruguay con ejemplares de herbario procedentes de Argentina, Bolivia, Brasil y Paraguay.…”

Advances in and perspectives on evolution in Bromeliaceae

“…Gilmartin & Brown, 1987;Varadarajan & Gilmartin, 1988). The use of morphological data in phylogenetic analysis decreased for many years before being re-established in the last decade, when micro-and macromorphological traits began to be employed at inter-and infrageneric levels (De Faria et al, 2004;Hornung-Leoni & Sosa, 2008;Almeida et al, 2009;Aguirre-Santoro et al, 2015;Da Costa et al, 2015;Donad ıo, Pozner & Giussani, 2015;Monteiro, Mantovani & Forzza, 2015;Saraiva, Mantovani & Forzza, 2015) and some studies in recent years have identified morphological characters with good taxonomic value for phylogenetic inferences (e.g. Versieux et al, 2010;De Faria, Vieira & Wendt, 2012;Magalhães & Mariath, 2012;Santos-Silva et al, 2013;Nogueira et al, 2015).…”

A New Species of the Mexican Tillandsia erubescens Group (Bromeliaceae)

“…Tillandsia is currently divided into six subgenera (Barfuss et al 2005, Donadío et al 2015, of which subgenus Tillandsia is the most diverse comprising over 269 species (sensu Gardner 1986). Gardner (1986) classified subgenus Tillandsia into five groups largely defined by characters of the corolla and androecium.…”