Protoparmelia capitata ( Ascomycota : Parmeliaceae ) : new record for South America

The sterile corticolous crustose lichen Protoparmelia capitata (Ascomycota: Parmeliaceae), recently described for southeastern North America, is reported as a new record for South America in the Serra da Jiboia mountain range, near the municipality of Santa Teresinha, in the state of Bahia, in northeastern Brazil. This species is locally common and is probably closely related to P. isidiata, which has the same pigmentation and medullary chemistry, P. capitata differing from P. isidiata in that the former features soredia rather than isidia.


Introduction
Protoparmelia is the main crustose genus in the family Parmeliaceae, which encompasses numerous foliose and fruticose genera and species.The name of the genus suggests that it is the ancestor of the family, and phylogenetically it is indeed a sister clade to the remainder of the genera now classified in the Parmeliaceae (Arup et al. 2007;Papong et al. 2011).It has the characteristic cupular exciple, a synapomorphic character common to all Parmeliaceae (Henssen 1995), and a character absent from a similar family, Lecanoraceae.Many Protoparmelia species share a unique character that is often overlooked: the presence of multiple cilia on the exterior surfaces of their ascospores (Brodo & Aptroot 2005).In addition, Protoparmelia species closely resemble Lecanora (the type genus of Lecanoraceae), except that all Protoparmelia species have a brown pigment in the cortex, much as in another Parmeliaceae genus, Neofuscelia.
The Serra da Jiboia mountain range of Brazil is in a transitional area between Atlantic Forest and caatinga (shrublands) vegetation, with a maximum elevation of 800 m.This fragment of Atlantic Forest is located within the municipality of Santa Terezinha, Bahia, NE Brazil, near the border with the municipality of Castro Alves, both municipalities being in the state of Bahia, in northeastern Brazil.This area can be considered a rain-forest enclave surrounded by caatinga and belongs to a disjunct set of mountains that extend from the southern coast of the state toward the north and northwest, stretching into the Baia de Todos os Santos region (Queiroz et al. 1996).
During a recent floristic survey of corticolous crustose lichens in fragments of the Atlantic Forest and caatinga in the state of Bahia, a large number of (mostly crustose) lichen species were found, several of them apparently new to science.One of the surveyed fragments was the Serra da Jiboia, in Santa Teresinha.Here, P. capitata was found to be quite abundant.The species is easily identified by its brown pigmentation, the huge hemispherical soralia and the presence of alectoronic acid in the medulla, which glows bright green under UV light.

Material and methods
Identification work was carried out in the Lichenology Laboratory of the Federal University of Sergipe, located in the city of Itabaiana, in the state of Sergipe, also in northeastern Brazil.Samples were examined with a stereomicroscope (EZ4; Leica Microsystems, Wetzlar, Germany) and a compound microscope (DM500; Leica Microsystems).Additional analyses were conducted at the Advice bureau for Bryology and Lichenology, in Soest, the Netherlands, also with a stereomicroscope (SZX7; Olympus America Inc., Center Valley, PA, USA) and a compound microscope (BX50; Olympus Optical, Tokyo, Japan) with interference contrast, connected to a digital camera (Coolpix; Nikon USA, Melville, NY, USA).The specimens analyzed during this study are preserved in the Herbarium of the Federal University of Sergipe Biosciences Department (code, ISE).Lendemer & Lumbsch, Lichenologist 40: 332. 2008.

Protoparmelia capitata
Thallus covering extensive areas of bark, crustose, ca.0.1 mm thick, very pale brown, corticate, a bit glossy, divided into more or less rectangular areoles 0.2-0.3mm in diameter, surrounded by a ca.0.3 mm-wide dark brown prothallus line.Soralia covering most of the thallus, hemispherical, mostly 0.6-1.5 mm in diameter, initially of the same color as the thallus, but thereafter showing white medullae.Soredia granular, somewhat glossy, the same color as the thallus, characteristically present only on the sides of the soralia.Apothecia unknown from Brazil but known from North America (see description in Lendemer & Lumbsch 2008).

Distribution
Known from North America (Alabama, Florida and Georgia; Lendemer & Lumbsch 2008) and now Brazil (Bahia).As far as is known at the moment, the three species of this species triplet have a different world distribution: P. pulchra is known only from Australasia; P. capitata is known from the American continent; and P. isidiata is pantropical.

Discussion
This species is easily confused with those of the sorediate genus Pertusaria (Pertusariaceae), from which it differs by having somewhat glossy, brownish soredia and medullary alectoronic acid, which is easily detected under UV light.Sorediate Pertusaria species invariably contain other medullary substances (xanthones, orcinol depsides, depsones, β-orcinol depsidones and depsides), which generally cause other reactions with spot tests or under UV light.The species that come closest in reaction are those with hypoprotocetraric acid, which also reacts strongly with UV light but glows white not green.This substance occurs in the common species Pertusaria subventosa Malme (Archer 1997), although that species often contains additional substances (which cause other reactions), such as lichexanthone (UV+ yellow).Other tropical corticolous crustose sorediate species (e.g., those in the genera Amandinea, Haematomma, Lecanora, Malmidea, Megalospora, Myeloconis, Myriotrema, Ocellularia, Rinodina) never contain alectoronic acid or other substances with similar reactions.Specimens observed -BRAZIL.Bahia, Santa Teresinha, Serra da Jiboia, on bark of tree, elevation ca.700 m, 23 Sep 2010, M. Cáceres 7895,7935,7946,7951 (all at ISE).