Description. [translated and modified from original treatment by Müller (1881)] Thallus very thin, 0.5-2 mm wide, orbicular, incompletely confluent into a composite thallus, vaguely diffused, minute whitish-cloudy, silvery-white, smooth. Vegetative diaspores absent. Photobiont chlorococcoid alga. Ascomata lecanorine apothecia, 0.25-0.33 mm diam., developed immersed to sessile, flat, not thick; disk brownish- or blackish-brown, opaque. Epithecium olivaceous; hymenium hyaline or hyaline-greenish; hypothecium brownish-olivaceous; paraphyses few, tips distinctly articulated, conglutinate, Asci 1-spored; ascospores hyaline, oblong-ellipsoid, 55-72 x 16-24 nm, muriform with transversal divisions ~20 transverse septa and 5-7 longitudinal septa.
Substrate and habitat. Foliicolous on evergreen leaves in forests.
Distribution. Pantropical, north into eastern North America; in North Carolina found in the Blue Ridge ecoregion (should be sought for throughout the state).
Notes. The entire life cycle of C. puiggarii has been described by Sanders (2014), providing an example detailed description of a full lichen life cycle.
Literature
Elix, J.A. & D.O. Øvstedal (2009) Lichen phytochemistry II: some species of Calopadia. Australasian Lichenology65: 7-9.
Müller, J. (1881) Lichenologische Beiträge XII. Flora (Regensburg). 64(7):100-112 (original description as Heterothecium puiggarii).
Sanders, W.B. (2014) Complete life cycle of the lichen fungus Calopadia puiggarii (Pilocarpaceae, Ascomycetes) documented in situ: propagule dispersal, establishment of symbiosis, thallus development, and formation of sexual and asexual reproductive structures. American Journal of Botany101(11): 1836-1848.