Selaginella subeffusa, a new spikemoss from Southeast Yunnan, China

Abstract

Based on extensive herbarium research of the Selaginella monospora group (incl. S. effusa, S. microclada, S. monospora, S. subdiaphana, and S. submonospora) and on molecular phylogenetic evidence, an additional new species to this group was discovered. It was collected from Dawei Mountain in southeast Yunnan, and here named as Selaginella subeffusa. The new species distinctly differs from similar species by its coriaceous and densely imbricate ventral leaves on main stems and branches, 2.2–3.1 mm long and 1.1–1.5 mm wide, with enlarged acroscopic base, and strongly overlapping stem and branches, and with denticulate margins; microspores verrucate and perforate. Phylogenetic analyses of three plastid regions (rbcL, atpI, psbA) showed that S. subeffusa clustered with S. submonospora and nested between the “S. microclada – S. effusa” clade and the “S. monospora” clade.