Phylogenetic position of the Himalayan genus Erioscirpus (Cyperaceae) inferred from DNA sequence data

Erioscirpus (Cyperaceae) is distributed mainly in the Himalayas, comprising two species: E. comosus and E. microstachyus. Recent authors have not recognized Erioscirpus as a distinct genus, but included it either in Eriophorum or Trichophorum, and always placed in tribe Scirpeae. However, as past authors have previously noted, Erioscirpus is quite different from Eriophorum and Trichophorum in some morphological features and in ecological preferences. In this study, we aimed to clarify the phylogenetic position of Erioscirpus using plastid and nuclear DNA sequence data for E. comosus from Nepal and Myanmar and E. microstachyus from India. We found that Erioscirpus was nested in tribe Cypereae, among the Ficinia clade with Dracoscirpoides, Ficinia, Hellmuthia, Isolepis and Scirpoides, which are predominantly distributed in the Mediterranean zones of the Southern Hemisphere. In contrast, Eriophorum and Trichophorum formed a clade with members of the tribes Cariceae, Dulichieae or Scirpeae, which are mainly distributed in the Holarctic zones of the Northern Hemisphere. It is thought that the common character, cotton-like long perianth bristles, shared by Erioscirpus, Eriophorum and Trichophorum, has evolved independently several times as a mechanism promoting wind dispersal. (c) 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170, 111.