Spiranthes igniorchis (Orchidaceae), a new and rare cryptic species from the south-central Florida subtropical grasslands

Abstract

Species complexes and cryptic species pose inherent challenges to taxonomists, systematists, and conservationists; Spiranthes (Orchidaceae) is a traditionally systematically challenging genus in which species complexes and cryptic species are a common phenomenon. Using an integrated approach of molecular phylogenetic, morphometric, and phenological data, we describe Spiranthes igniorchis, a new and rare species from frequently burned subtropical grasslands of Avon Park Air Force Range in south-central Florida. Spiranthes igniorchis is closely related and morphologically similar to Spiranthes longilabris, however S. igniorchis has smaller-sized flowers that bloom in the wet season, in contrast to S. longilabris, which has larger sized flowers that bloom in the dry season. We also present a discussion of its distinguishing characteristics and the challenges associated with species identification within Spiranthes.