Platanthera sparsiflora is a variable species to which Limnorchis ensifolia and L. laxiflora have been referred. Recently, authors have adopted L. ensifolia for a group of plants that have also been referred to L. laxiflora and P. sparsiflora. None of these existing names apply to a recently delineated but related group, here described as the new species P. tescamnis. This species is distinguished by a small column with short rostellum lobes that position the viscidia above the orifice of the spur. The species exhibits ecological preferences that are unique in the group, occurring at relatively low elevations and in comparatively dry habitats in a hot, arid region. It occurs across the Great Basin and Colorado Plateau and bordering areas in California, Nevada, Arizona, Utah, and Colorado.