Hypogymnia recurva and Hypogymnia wilfiana spp. nov., two new lichens from western North America

Hypogymnia metaphysodes was first described from Japan and Sakhalin, and later reported from western North America. Here we show that the North American material currently referred to H. metaphysodes differs from that species not only morphologically and chemically, but also in ascospore size and shape. We also show that the North American material is in fact heterogeneous, and can be assigned to two well-defined species here described as new: Hypogymnia recurva sp. nov. and H. wilfiana sp. nov. Both of these lichens contain distinctive secondary metabolites: vittatolic acid in the case of H. recurva, and 2-methylene-3-carboxy-18-hydroxynonadecanoic acid (apinnatic acid''), reported here for the first time from Hypogymnia, in H. wilfiana. Both of our new species are so far known only from western North America, where they occur primarily as epiphytes on the branches of conifers. Hypogymnia metaphysodes s. str. has not yet been reliably reported from this region and should be excluded from the North American lichen flora.