Systematic analysis of the genus <i>Eriocaulon</i> L. in India based on molecular and morphological evidence

The present study is the first-ever comprehensive molecular systematic study of Indian <i>Eriocaulon</i> species based on the critical appraisal of the freshly collected 552 accessions of 66 <i>Eriocaulon</i> spp. The genus <i>Eriocaulon</i> L. (Eriocaulaceae) is one of the most diverse genera of Eriocaulaceae and around one-quarter of the world’s representation is in India. The taxonomy of the genus has been challenging due to high intraspecific and low interspecific variation. With about 70% of Indian species endemic to the country, sparse representation in earlier phylogenetic studies did not provide phylogenetic resolution of Indian species. A critical analysis of morphology including microscopic seed surface characters of 55 species is presented here for the first time. Phylogenetic analyses based on ITS and <i>trnL–F</i> data yielded three major clades of Indian <i>Eriocaulon</i> species. Based on the morphological and molecular data, <i>Eriocaulon baramaticum</i>, <i>E. govindiana</i>, <i>E. gulnarparianum</i>, <i>E. idukkianum</i>, <i>E</i>. <i>maharashtrense</i> and <i>E. pradeepii</i> have been synonymized. Also, <i>Eriocaulon rhodae</i> has been reinstated. Molecular data exhibited little congruence with the earlier available taxonomic treatments for Indian species. Several morphological characters were mapped onto a phylogeny and none were found to characterize monophyletic groups.