Two North American species are known, viz. Peridermium ornamentale (Arthur 1901), described based on an aecial host collection on Abies lasiocarpa from Washington, and Pe. holwayi (Sydow and Sydow 1903), introduced for aecial host spore stages (0 and I) found on Pseudotsuga menziesii in Canada, British Columbia. Arthur (1934) reduced both species names to synonymy with Pucciniastrum goeppertianum, but Faull (1939) disagreed and emphasized that collections of C. goeppertiana s. lat. are morphologically differentiated into two taxa, viz. C. goeppertiana s. str. in eastern North America and a taxon in western North America for which the name Pe. ornamentale is available. The existence of a different taxon of Calyptospora, possibly a species of its own, in western North America was already assumed by Weir (1926). In the western taxon, Pe. ornamentale, the aecia and spermogonia (type 3, according to Cummins and Hiratsuka 2003) are formed on current year needles in late summer or early autumn, whereas in P. goeppertianum from eastern North America aecia are formed in early summer, but spermogonia are lacking or sometimes developed only in degenerated form (Hiratsuka et al. 1967). Pe. holwayi has usually been reduced to synonymy with Pe. ornamentale, but the genuine identity of this species, based on an aecial host spore stage on Pseudotsuga menziesii, remains unclear and needs further detailed examinations, including phylogenetic analyses. Aecia of P. holwayi occur on Pseudotsuga, and are formed on previous year needles in early summer, in contrast to P. ornamentale growing on Abies and forming aecia on current year needles in late summer or early autumn. Vogler and Bruns (1998) generated sequence data retrieved from Calyptospora goeppertiana s. lat. (= Peridermium ornamentale) on Abies grandis (native to the Pacific Northwest and Northern California), belonging to the western taxon in North America. These sequences ... cluster in sister position to the European sequences of C. columnaris. Thus, these preliminary data support Weir’s (1926) and Faull’s (1939) careful examinations and conclusions that there is a different Calyptospora species in western North America for which the name Pe. ornamentale is available. However, this can only be the very first step towards a revision of the C. goeppertiana complex in North America. The taxonomic and phylogenetic position of Calyptospora goeppertiana in eastern North America, although morphologically indistinguishable from European collections of this species, is still unproven, i.e. it remains open whether the eastern North American taxon is actually conspecific with C. goeppertiana s. str. or if a third species may exist.
The nomenclature of the two species involved in this complex can be summarized as follows:
Calyptospora columnaris ... Holotype: Germany, Lusatia [herb. Schweinitz], s. n., on Abies alba [Pinus picea] ...
Calyptospora ornamentalis(Arthur) M. Scholler & U. Braun, comb. nov. ... Holotype: USA, Washington, Mount Paddo, on Abies lasiocarpa,
