Flora of New Zealand Series

Thallus crustose or squamulose-placodioid, sometimes verrucose- or granular-furfuraceous, effuse or lacking, attached to substrate by medullary hyphae, effigurate or lobed and subfoliose at margins, corticolous, muscicolous or saxicolous, heteromerous, yellow or yellowish-orange, or red or brown-red, occasionally blackened or greyish-white, K+ purple (anthraquinones) or K-. Photobiont green, Trebouxia. Apothecia lecanorine, yellow, orange, rust red, or brownish, rounded, appressed or sessile. Hypothecium colourless. Paraphyses simple, septate, capitate. Asci 8-spored. Ascospores colourless, thick-walled, polarilocular, mainly with 2 locules, one species with three locules. Pycnidia immersed. Conidia short, straight, cylindrical.

Caloplaca, included in the family Teloschistaceae, is a genus of cosmopolitan distribution containing c. 450 species. Species occur widely in New Zealand, occupying habitats from s.l. to 3000 m. It is well developed on rocky shores in all parts of the country and is commonly found also on limestone outcrops, while one species occurs associated with species of the moss Andreaea in fellfield and high-alpine vegetation. Although widely distributed and easily recognised by the colour of the apothecia, and often also of the thallus, it is still poorly collected and needs serious study in New Zealand.

Much information on the genus is contained in Magnusson [ Göteborgs K. Vetensk.-O. vitterh. Samh. Handl. ser. B, 3/1: 1-17 (1944)], Poelt. [ Mitt. bot. St.Samml., Münch. 2: 11-31 (1954)], Wade [ Lichenologist 3: 1-28 (1965)], Nordin [ "Caloplaca, sect. Gasparrinia i Nordeuropa" Uppsala (1972 - in Swedish)], and Hafellner and Poelt [ J. Hattori bot. Lab. 46: 1-41 (1979)]. J. Santesson [ Phytochemistry 9: 2149-2166 (1970)] records the following anthraquinones from Caloplaca : Emodin, parietin, fallacinol, fallacinal, parietinic acid, xanthorin, 2-chloroemodin, fragilin and 1-O-methylfragilin, and gives an exhaustive list of the occurrence of these compounds in 230 species, several of which occur in New Zealand.

The following account of Caloplaca in New Zealand is based on an examination of many types recorded from New Zealand supplemented with a limited range of more recently collected material. Twenty-one species are discussed. Taxa with biatorine fruits (i.e., lacking a thalline margin) are referred to Blastenia.