New Cladonia Species from Western North America: Cladonia artuata and C. poroscypha

Abstract

The name Cladonia Vainio (Ascomycotina: Lecanorales) has been mis- takenly associated with several taxa in Western North America. A very broad circumscription of C. worldwide has resulted in the neglect of several distinct and interesting taxa, and has obscured the understanding of their morphology, biology, and biogeography. Taxonomic concepts that have been applied to C. carassensis in western North America are discussed, including several Cladonia species with morphological affinities to section Perviae that possess a more or less con- tinuous cortex and thamnolic or barbatic acid or both. Two new species, C. poroscypha and C. artuata, are described. Cladonia was described from south- eastern Brazil by Vainio (1887) and was later given a broad circumscription by Asahina (1942) and Sandstede (1931). Adopting the concepts of these workers, Evans (1950) attributed to C. a worldwide geographical distribution and a wide range of morphological characters. In agreement with this usage, the name C. came to be ap- plied to collections with perforated axils, a more or less continuous, esorediate cortex, and thamnolic or barbatic acid or both. On this basis, Thomson (1967) listed C. from western North America, including both of the forms discussed in Evans-fo. regularis Vainio and fo. subulata (Sandst.) Evans. Tucker and Jordan (1979) included it in their catalog of California lichens, and Hale and Cole (1988) also listed C. for Cali- fornia. Ahti (pers. comm.), Krog (1968), and Poelt (1969) encountered problems when attempting to circumscribe taxa within the so-called C. group from various Old and New World localities. Study of the type material of C. in- dicates that C. s.s. is not found in North America, agreeing with Krog (1968). Evans' concept of C. fo. regularis from the western Unit- ed States was based on material from Oregon that is treated in this paper as C. artuata. Evans' de- scription of C. fo. subulata was based on a collection from California, which is also in- cluded here as a new species. The two new species from western North America, as well as C. thiersii Hammer, are morphologically and chemically com- parable to one another and to C. carassensis, but each possesses a distinct suite of characters, as dis- cussed below.