TheSticta filixmorphodeme (Ascomycota:Lobariaceae) in New Zealand with the newly recognized speciesS. dendroidesandS. menziesii: indicators of forest health in a threatened island biota?

Abstract

AbstractWe present a phylogenetic revision of theSticta filixmorphodeme in New Zealand. This non-monophyletic group of early diverging clades in the genusStictais characterized by a stalked thallus with a green primary photobiont and the frequent formation of a dendriscocauloid cyanomorph. Traditionally, three species have been distinguished in New Zealand:S. filix(Sw.) Nyl.,S. lacera(Hook. f. & Taylor) Müll. Arg. andS. latifronsA. Rich., with two cyanomorphs separated under the namesDendriscocaulon dendriothamnodesDughi ex D. J. Galloway (traditionally associated withS. latifrons) andD. dendroides(Nyl.) R. Sant. ex H. Magn. (traditionally associated withS. filix).Sticta lacerawas not included in the present study due to the lack of authentic material (all specimens originally identified under that name and sequenced clustered withS. filix);S. filixwas confirmed as a distinct species whereasS. latifronss. lat. was shown to represent two unrelated species,S. latifronss. str. and the reinstatedS. menziesiiHook. f. & Taylor. The cyanomorphs ofS. filixandS. latifronsare not conspecific with the types of the namesD. dendriothamnodesandD. dendroides, respectively; theD. dendriothamnodescyanomorph belongs to the Australian taxonSticta stipitataC. Knight ex F. Wilson, which is not present in New Zealand, whereas theD. dendroidescyanomorph corresponds to a previously unrecognized species with unknown chloromorph, recombined here asSticta dendroides(Nyl.) Moncada, Lücking & de Lange. Thus, instead of three species (S. filix,S. lacera,S. latifrons) with their corresponding cyanomorphs, five species are now distinguished in this guild in New Zealand:S. dendroides(cyanomorph only),S. filix(chloro- and cyanomorph),S. lacera(chloromorph only),S. latifrons(chloro- and cyanomorph) andS. menziesii(chloro- and cyanomorph). A key is presented for identification of the chloromorphs and the dendriscocauloid cyanomorphs of all species. Semi-quantitative analysis suggests that species in this guild are good indicators of intact forest ecosystems in New Zealand and that the two newly recognized species,S. dendroidesandS. menziesii, appear to perform particularly well in this respect. The use of lichens as bioindicators of environmental health is not yet established in New Zealand and so, based on our results, we make the case to develop this approach more thoroughly.