Spiranthes stylites is another long overlooked Asian Spiranthes with an unusual Sylvian habitat

<p>We reexamine the taxon <em>Spiranthes stylites</em>, currently synonymized under <em>S. australis,</em> finding multiple lines of evidence from molecular phylogenetics, phenology, morphology, and habitat differences to support its distinction from other members of the <em>Spiranthes sinensis</em> species complex. Compared to its closest relative <em>S. australis</em>, <em>S. stylites</em> blooms earlier (June-early July vs. mid July-September), has consistently white tubular flowers (vs. commonly pink and pseudocampanulate), a distinctly long-clawed labellum (vs. shortly clawed), slender labellum nectar callosities (vs. globose), a proportionally larger column foot (ca. 50% of the length of the entire column vs. ca. 25%), and occurs in closed canopy woodlands (vs. open graminoid habitats). <em>Spiranthes stylites</em> is the only <em>Spiranthes</em> in the Eastern Hemisphere to have a woodland habitat. The recognition of <em>S. stylites</em> helps support white colored flowers as the plesiomorphic and most common floral condition in the complex, and indicates pink colored flowers likely arose independently in<em> S. australis</em> and <em>S. sinensis s.s.</em></p>