Quechua, a New Monotypic Genus of Andean Spiranthinae (Orchidaceae)

The systematic position of the little-known Andean species Spiranthes glabrescens, previously known only from Peru but here recorded for the first time from Ecuador, was investigated by means of parsimony and Bayesian analyses of cpDNA and nuclear DNA sequences. Our results indicate that this species is only distantly related to both Spiranthes and Cyclopogon, the genera in which it has been included by previous taxonomists. Instead it is recovered as sister to a clade formed by Eurystyles and Lankesterella, with strong support from the Bayesian analysis. The new, monotypic genus Quechua is proposed to accommodate former S. glabrescens, which differs from both Eurystyles and Lankesterella in habit as well as in vegetative and reproductive characters. The main ecological and structural features of Quechua glabrescens are discussed and compared with those of other genera of Spiranthinae.