The Lichen Genus Aspidelia Stirt.

Abstract

The name Aspidelia Stirt. is invalid. The constituent species of this genus, A. beckettii Stirt. from New Zealand and A. wattii Stirt. from the Himalayas, are identified as Parmelia tenuirima Hook. & Tayl. and Cetraria sanguinea Schaer. respectively. In the course of monographing the genus Cetraria and certain related groups in the Parmeliaceae, I have found it necessary to clarify certain obscure generic names suspected to refer to these plants. One of these is Aspidelia, a name proposed by Stirton in 1899 and a genus to which no major reference in the taxonomic literature has subsequently ever been made. Two species were described by Stirton to constitute the new genus Aspidelia. Nomenclaturally, however, the genus can be dismissed as invalidly published because there was no description of it apart 1 Research carried out under National Science Foundation Grant GB1239. 2 Department of Botany, Duke University, Durham, North Carolina 27706. This content downloaded from 207.46.13.111 on Tue, 09 Aug 2016 04:59:10 UTC All use subject to http://about.jstor.org/terms 114 THE BRYOLOGIST [Volume 69 from the diagnoses of the new species themselves (International Code, Art. 41). Consequently the names of the species are invalid too (Art. 43). The two species referred to Aspidelia A. beckettii Stirt. from New Zealand and A. wattii from the Himalayas were thought by Stirton to be closely related to each other and sufficiently distinct from other Parmeliaceae, notably Parmelia itself, to constitute a new genus. The supposedly unique character of Aspidelia was the spermogonia clustered in raised tubercules or bullae. The holotype specimens of both species were seen through the courtesy of the Keeper of Botany of the British Museum (Natural History). Both specimens have large, conspicuous tubercles on the upper surface. These tubercles, however, do not contain pycnidia (=spermogonia) at all but instead the fruiting bodies of some parasitic fungus or fungi. The genus Aspidelia and the two species that constitute it are based on pathological material. Aspidelia beckettii, which received the more detailed original description of two species, is referrable to Parmelia. Mason E. Hale, Jr., who is currently monographing that genus, has identified the type of A. beckettii as Parmelia tenuirima Hook. & Tayl. I have identified the constituents of this specimen as salacinic acid (by crystals in the G.A.o-T and K,CO:/KOH solutions and by paper chromatography) and atranorin (crystals in the G.A.o-T solution). Aspidelia wattii is based upon a very badly infected specimen of Cetraria sanguinea Schaer. The specimen has a certain phytogeographic interest quite apart from its nomenclatural significance in that it is one of the apparently few specimens of Cetraria sanguinea ever collected from the mainland of Asia, the species being best known from Java where it seems to be one of the most abundant macrolichens. In the type specimen in question here, Chicita F. Culberson found anziaic acid (by chromatography) and atranorin (by crystals in the G.E. and G.A.o-T solutions and by chromatography), the same substances as those elaborated by the species in Java. In summary, the nomenclatural and taxonomic disposition of Aspidelia is as follows: Aspidelia Stirt., Trans. & Proc. New Zealand Inst. 32: 81. 1899 (Published: June, 1900).-Invalid name (Art. 41). Aspidelia beckettii Stirt., Ibid., 82: 81. 1899 (1900). Type: New Zealand, Beckett. (Holotype BM!). Invalid name (Art. 43). Identity: Parmelia tenuirima Hook. & Tayl. (fide M. E. Hale, Jr.). Aspidelia wattii Stirt., Ibid. 82: 82. 1899 (1900). Type: Himalayas, Lingabelah Range, 12,000 ft, Watt 7070. (Holotype BM!). Invalid name (Art. 43). Identity: Cetraria sanguinea Schaer.