Pedicularis aurantiaca and Pedicularis densiflora (Orobanchaceae): Taxonomy, Phenology and Floral Morphological Variation

We investigated patterns of infraspecific variation among populations of Pedicularis densiflora, including populations formerly recognized as P. densiflora subsp. aurantiaca. Several statistical analyses (UPGMA, ANOVA, and PCA) were conducted on floral traits measured in the field. All three statistical analyses indicated consistent differences in floral morphology among populations. These differences were confirmed by a review of over 1000 herbarium specimens. Two series of populations were separated, and two species recognized, Pedicularis aurantiaca and P. densiflora. Pedicularis aurantiaca had large calyces with floral tubes included at anthesis, reduced lower labia, and enlarged galea openings. Pedicularis densiflora had short calyces with fully exserted floral tubes, enlarged lower labia, and smaller galea openings. Taxonomy, phenology, and floral differences are discussed in the context of previously published data on pollinator visitation.