A key to the corticolous microfoliose, foliose and related crustose lichens from Rondônia, Brazil, with the description of four new species. (23rd October 2014)

• Record Type: Journal Article
• Authors: APTROOT, André; CÁCERES, Marcela Eugenia da Silva
• Is Part Of: Lichenologist. Volume 46:Part 6(2014:Nov.)
• Page Start: 783
• Page End: 799
• Publication Date: 2014-10-23
• Subjects: Lichens -- Periodicals; 579.7
• DOI: 10.1017/S0024282914000358
• Languages: English
• ISSNs: 0024-2829

Abstract

<abstract abstract-type="normal"> <title>Abstract</title> <p>A key is given to the foliose and squamulose lichens known so far from Rondônia, including also corticolous crustose lichens with a chlorococcoid alga. The foliicolous <italic>Lecanorales</italic> found are also listed. The following four new corticolous <italic>Lecanorales</italic> are described from Rondônia: <italic>Calopadia granulosa</italic> with a granular, corticate thallus and ascospores 1 per ascus, 33–38×10·5–13·0 µm; <italic>Crustospathula amazonica</italic> with irregularly capitate to nearly globose, <italic>c.</italic> 0·2–0·4 mm diam. soralia on cartilaginous stalks; <italic>Flavoparmelia plicata</italic> with a thallus containing usnic and protocetraric acids, with laminal, irregular, globose to cylindrical isidia which are often easily abraded and showing the whitish medulla, but not sorediate or postulate; <italic>Physcidia striata</italic> with ascending squamules, without hypothallus, often with laminal isidia in defined areas towards lobe tips of some, usually sterile lobes, and often with biatorine apothecia with ascospores simple to 1-septate, (6·2–)7·5–10·0×(2·5–)3·0–3·5 µm. In the whole lichen flora of the lowland rainforest region of Rondônia, the following traits can be discerned: foliose lichens amount to only 17 species (2·7% of nearly 600), 33 (5·5%) are squamulose, while the vast majority (91·8%) are crustose. Cyanobacteria are present in only 6 (1%) species. A chlorococcoid alga present in <italic>c</italic>. 100 (16%), 12 of which (2%) have a myrmecioid alga. The remainder of the species, a staggering 83%, have trentepohlioid alga, including 6 (1%) with <italic>Phycopeltis</italic>. In neotropical lowland rainforest, the vast majority of the lichens are crustose and contain a trentepohlioid alga, and the <italic>Arthoniales</italic>, <italic>Graphidaceae</italic> and pyrenocarpous lichens are the main groups, each accounting for roughly a quarter of the lichen biodiversity.</p> </abstract>