Crespo et al. (Reference Crespo, Kauff, Divakar, del Prado, Pérez-Ortega, Amo de Paz, Ferencova, Blanco, Roca-Valiente and Núñez-Zapata2010) pointed out that the Canoparmelia crozalsiana group formed a sister clade to that of Parmotrema s. str., and that it was not related to the type species of Canoparmelia, C. texana (and 39 allied species), which forms a well-supported basal group to the entire parmotremoid clade (i.e. Austroparmelina, Flavoparmelia, Flavopunctelia, Nesolechia, Parmotrema s. str., and Punctelia). The C. crozalsiana group and Parmotrema s. str. together form the sister group of Flavoparmelia, which is distinguished in having bifusiform and not filiform conidia, but characteristically shares the thick-walled ascospores. The thalli of the C. crozalsiana group are rather distinctive with a characteristic wrinkled and reticulately ridged to coarsely foveolate upper surface, sometimes almost areolate and with pieces tending to break away, often also becoming pruinose, at least in parts, and always lack usnic acid. Stictic and constictic acids are the medullary extrolites in three of the four known species. Apothecia and pycnidia are rarely seen in most species, but I have examined them in C. inhaminenses (BM 000731261—holotype) where the rather thick-walled ascospores and filiform conidia are typical of Parmotrema. The conidia of C. crozalsiana have also been reported as filiform by Swinscow & Krog (Reference Swinscow and Krog1988).
Generic rank is not appropriate for this clade as there are no features from the ascomata or conidiomata that distinguish it from its close sister group Parmotrema s. str. A new subgeneric name for these lichens is therefore introduced here and the necessary new combinations into Parmotrema are made.
Parmotrema subgen. Crespoa D. Hawksw. subgen. nov
MycoBank No.: MB561251
Similis Parmotremis subgen. Parmotremis sed differt in thallis supernis reticulatis ad foveolatis vel subareolatis, e plerumque in parte pruinosis.
Typus: Parmelia crozalsiana B. de Lesd. ex Harm.
Etymology. The subgeneric name honours Ana M. Crespo de Las Casas, in recognition of the lead she has taken in rationalizing generic and specific concepts in the parmelioid lichens using molecular phylogenetic approaches.
Key to the recognized species
1 Soredia present; apothecia generally absent; medulla K + yellow (stictic acid complex) ... 2
Soredia absent; apothecia generally present; medulla K+ yellow or K− ... 3
2 (1) Lobes irregulary rounded, 2–5 mm wide ... P. crozalsianum
Lobes elongated, 1–2·5 mm wide ... P. carneopruinatum
3 (1) Medulla K− (protocetraric acid) ... P. schelpei
Medulla K+ yellow (stictic acid complex) ... P. inhaminenses
Descriptions and photographs of these four species are provided by Hale (Reference Hale1976). All are essentially tropical, although Parmotrema carneopruinatum is also known from southern France and Italy (as Parmelia sbarbaronis) and P. crozalsianum extends more widely northwards into southern Europe and the USA.
Parmotrema carneopruinatum (Zahlbr.) D. Hawksw. comb. nov
MycoBank No.: MB561252
Basionym: Parmelia carneopruinata Zahlbr., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 111: 419 (1902).
Synonyms: Pseudoparmelia carneopruinata (Zahlbr.) Hale, Phytologia 29: 189 (1974).—Canoparmelia carneopruinata (Zahlbr.) Elix & Hale, in Elix et al., Mycotaxon 27: 278 (1986).
Parmelia sbarbaronis B. de Lesd., Bull. Soc. Bot. Fr. 23: 278 (1923).
This taxon has sometimes been subsumed with P. crozalsianum, and a more detailed study of these two species is required to ascertain if they should be retained as distinct.
Parmotrema crozalsianum (B. de Lesd. ex Harm.) D. Hawksw. comb. nov
MycoBank No.: MB561253
Basionym: Parmelia crozalsiana B. de Lesd. ex Harm., Lich. Fr. 4: 555 (1909).
Synonyms: Pseudoparmelia crozalsiana (B. de Lesd. ex Harm.) Hale, Phytologia 29: 189 (1974).—Canoparmelia crozalsiana (B. de Lesd. ex Harm.) Elix & Hale, in Elix et al., Mycotaxon 27: 278 (1986).
Parmotrema inhaminenses (C. W. Dodge) D. Hawksw. comb. nov
MycoBank No.: MB561254
Basionym: Parmelia inhaminensis C.W. Dodge, Ann. Mo. bot. Gdn 46: 130 (1959).
Synonyms: Pseudoparmelia inhaminensis (C.W. Dodge) Hale, Phytologia 29: 190 (1974).—Canoparmelia inhaminensis (C.W. Dodge) Elix & Hale, in Elix et al., Mycotaxon 27: 278 (1986).
Parmotrema schelpei (Hale) D. Hawksw. comb. nov
MycoBank No.: MB561255
Basionym: Parmelia schelpei Hale, Bryologist 75: 344 (1972).
Synonyms: Pseudoparmelia schelpei (Hale) Hale, Phytologia 29: 191 (1974).—Canoparmelia schelpei (Hale) Elix & Hale, in Elix et al., Mycotaxon 27: 279 (1986).
I thank Pradeep Divakar and Ana Crespo for stimulating discussions of the most appropriate taxonomic treatment of these species. This work was undertaken while in receipt of funding from the Ministerio de Ciencia e Innovación of Spain under Proyecto CGL2008-01600.
