Areas of endemism of the North American species of Tigridieae (Iridaceae)

Abstract

The tribe Tigridieae (Iridoideae: Iridaceae) is a New World group with centres of diversity in Mexico and Andean South America. North America harbours 67 of the 172 species recognised within the tribe, 54 being endemic. Our aims were to identify areas of endemism of the North American Tigridieae using endemicity analysis (EA) and to infer their relationships using parsimony analysis of endemicity (PAE). A data matrix with 2769 geographical records of Tigridieae was analysed. The EA allowed to identify six consensus areas of endemism in Mexico. The PAE resulted in one cladogram with four clades and the following five biotic components: northern Mexico, western Mexico, central Mexico, southern Mexico and central–southern Mexico. The richness analysis of these areas of endemism indicated that the greatest concentration of species is located in central Mexico, with 14 species in one grid-cell. Grid-cells with 12 species each were identified in low western Mexico, high western Mexico, southern Mexico and central–southern Mexico. This last area is characterised by the greatest endemism, including nine species. The formation of the Transmexican Volcanic Belt seems to have been a key element to explain the diversification of North American Tigridieae.

Evolutionary history of the flora of Mexico: Dry forests cradles and museums of endemism

“…Patterns of WE and WPE were similar, and particularly for endemism are consistent with earlier research on a number of taxonomic groups: (i) ferns, in which species richness was identified in the SE and in Chiapas, and weighted endemism in several areas in the Sierra Madre Oriental, in the Trans‐Mexican Volcanic Belt and Sierra Madre del Sur (Sanginés‐Franco et al, ); (ii) gymnosperms, for which areas of endemism coincided in the Sierra Madre Oriental and a small area in Oaxaca (Contreras‐Medina & Luna‐Vega, ); (iii) the monocot tribe Tigridieae (Iridaceae), for which endemism coincided in the eastern part of the Trans‐Mexican Volcanic Belt and the Sierra Madre Oriental, as well as in the Tehuacán Valley and in the Sierra Madre del Sur (Munguía‐Lino et al, ); (iv) oaks, Quercus spp., for which areas of endemism were identified in the Sierra Madre Occidental and in the Trans‐Mexican Volcanic Belt (Rodríguez‐Correa et al ); (v) the genus Bursera in which three areas of endemism were identified on the Central Mexican Pacific Coast, in the western Balsas River Basin and in the Tehuacán Valley (De‐Nova et al, ; Gámez et al, ); and (vi) cacti from the Chihuahuan Desert where high degrees of endemism were identified on the Mexican Plateau, as well as in the southern area of the Sierra Madre Oriental (Hernández & Gómez‐Hinostrosa, ). In addition, for one functional group, the monocot geophytes, significant areas of endemism were identified in the Trans‐Mexican Volcanic Belt, the Sierra Madre Oriental, and in the Tehuacán Valley, which also agrees with our results (Sosa & Loera, ).…”

“…2). Earlier research has focused solely on endemism for certain plant groups such as the Tigridieae (Iridaceae), Bursera, oaks, cacti, monocot geophytes and ferns, and a number of studies have focused on patterns of species richness and endemic taxa in certain regions of Mexico (D avila-Aranda et al, 2004;Contreras-Medina & Luna-Vega, 2007;Riemann & Ezcurra, 2007;Hern andez & G omez-Hinostrosa, 2011;De-Nova et al, 2012;G amez et al, 2014;Rodr ıguez-Correa et al, 2015;Sangin es-Franco et al, 2015;Mungu ıa-Lino et al, 2016;Sosa & Loera, 2017;De-Nova et al, 2018). The majority of these studies identified the southern regions of the Sierra Madre Oriental and Sierra Madre Occidental mountain ranges, the Trans-Mexican Volcanic Belt and the Tehuac an Valley as having high degrees of endemism.…”

Identification of areas of endemism in the Mexican cloud forests based on the distribution of endemic epiphytic bromeliads and orchids

“…Furthermore, Morrone (2017) reported 35 endemic species of plants and animals from this region, suggesting that it is a rich area in endemics. Munguía-Lino et al (2016) using the Tigridieae plant family species from North America recognized six areas of endemism, four of them (Low and High western Mexico, Southern Mexico and Central-southern Mexico) have a very similar geographic location with three areas of endemism (Western Mexico, Southern Mexico and Northern Oaxaca) recognized in the present work. On the other hand, Escalante et al (2009) using Mexican mammals' data, recognized 16 areas of endemism, unfortunately, some of them overlaps, so that more than one area of endemism coincides, in general, with the geographical position of the five areas recognized here.…”

Richness, geographic distribution patterns, and areas of endemism of selected angiosperm groups in Mexico

“…). Even though most species are restricted to Mexico, some extend their geographical distributions north into the USA, east into the Caribbean Islands and south to Central and South America (Vargas‐Amado et al, ; Munguía‐Lino et al, , ). For our purpose, Mexico is part of North America based on the Level 1 concept of the International Working Group on Taxonomic Databases for Plant Sciences (Brummitt, ).…”