Twenty thousand leagues of disjunctions: biogeographic patterns of the Schoenoxiphium clade (Carex, Cyperaceae)

BRUCE A. FORD; SANTIAGO MARTÍN-BRAVO; CARMEN BENITEZ-BENITEZ ; SABINA DONADÍO; MODESTO LUCEÑO; PEDRO JIMÉNEZ-MEJÍAS

Málaga

Conferencia; 9th Biennial Conference of the International Biogeography Society; 2019

Sociedad IberoAmericana de BioGeografía

The so-called Schoenoxiphium clade of the genus Carex (Cyperaceae) is an assemblage of sedges belonging to different, non-monophyletic sections with unusual disparate morphological characteristics. Remarkably, the group is quite well-defined from a molecular point of view. It is formed by 60 species showing an interesting Gondwanan distribution pattern in the Southern Hemisphere (with disjunct taxa in South America, South Africa, and New Zealand). Additionally, it has also a few representatives in the Northern Hemisphere, depicting a Rand-Flora distribution around the Sahara desert (mountains of tropical E Africa, Macaronesia, and the Mediterranean Basin). Only C. pulicaris is widely distributed across Europe. The group is somehow ecologically diversified, with mostly temperate preferences, but with some species also occurring in subdesertic steppes and alpine environments. The clade has been dated as one of the earliest in divergence among Carex sedges (25-28 Mya; Upper Oligocene). Here we present a phylogenetic hypothesis using an almost complete sampling of the group (58 spp, 96% of the clade) and based on 2 nuclear (ETS, ITS) and 2 plastid markers (matK, rps16). We performed ancestral area reconstruction analyses to evaluate the relative contribution of vicariance vs. long-distance dispersal/geodispersal processes in order to get insights into the evolutionary history behind the striking biogeographic patterns found in this group of sedges.