[Wikipedia] Rarity, Range, Description: Platanthera colemanii is a rare species of orchid known by the common names Coleman's piperia and Coleman's rein orchid. It is endemic to California, where it is known from scattered occurrences along the Sierra Nevada and one disjunct location in Colusa County, California. It grows in coniferous forests and chaparral in deep sandy substrates. It was differentiated from the very similar Platanthera unalascensis in 1993.The flower can be distinguished from that of P. unalascensis by its shorter spur relative to its lip. (link added by Mary Ann Machi)