Opuscula Philolichenum, 11: 31-35. 2012. *pdf available online 3January2012 via (http://sweetgum.nybg.org/philolichenum/) Some Notes on Acarosporaceae in South America 1 KERRY KNUDSEN ABSTRACT. – Three species and one genus are reported new for South America (all are from Ecuador): Acarospora americana, Caeruleum heppii, and Polysporina simplex. Acarospora catamarcae and A. thelomma are verified as distinct species occurring in Argentina. Acarospora punae is placed in synonymy with A. thelomma and lectotypes are designated for both names. Acarospora sparsiuscula is also verified as a distinct species, originally described from Argentina and here reported from the Galapagos Islands in Ecuador. A total of twenty-seven species of Acarosporaceae are recognized as occurring in South America in this ongoing taxonomic series. KEYWORDS. – Biodiversity, taxonomy. INTRODUCTION This paper is a new installment of a continuing series of studies Acarosporaceae in South America (Knudsen 2007a; Knudsen & Flakus 2009; Knudsen et al. 2008, 2010, 2011, in press.). In this paper I examine two species described by Magnusson (1947) from South America, Acarospora catamarcae H. Magn. and A. sparsiuscula H. Magn., and two species described by Lamb (1947) from South America, A. thelomma I.M. Lamb and A. punae I.M. Lamb. During the period of this study I also examined specimens collected by Zdenek Palice in Ecuador (PRA) and by Andre Aptroot on the Galápagos Islands in Ecuador (CDS) as well as specimens from Graz (GZU). A current checklist with literature references is also included. Species are only included in the checklist if they have been verified by myself as part of this continuing study. Taxonomy is experimental. A species concept generated by the study of specimens is a hypothesis. Once a species is named, then it can be further tested by identifying new collections, and revised with further taxonomic studies as well as with molecular, biogeographical, and populational studies. In this series of taxonomic studies, most of the species concepts are represented by a small sample of specimens. In the future, I expect changes in these species concepts and accepted nomenclature.. The main aim of this series is to stimulate more extensive collections and field observations of Acarosporaceae in South America, as well as studies by teams using a variety of tools, including molecular phylogenetic analysis. MATERIALS AND METHODS Specimens were studied from CDS, GZU, PRA, UCR, and UPS. Specimens were prepared with hand sections and studied using standard light microscopy, unless otherwise stated in text. Measurements were made in water. Amyloid reactions tested with Lugol’s Solution (IKI), with or without pretreatment with KOH (K), and the structures were studied in 5% K. Standard spot tests were performed but no thin- layer chromatography was performed. NOTES 1 KERRY KNUDSEN – The Herbarium, Department of Biology and Plant Sciences, University of California, Riverside, CA 92521, U.S.A. – e-mail: [email protected] 31 1) Acarospora americana H. Magn., Kungl.-Akad. Handlingar 7(4): 198. 1929. TYPE: U.S.A. ILLINOIS. KANE CO.: sine loc., 1895, on silicate rock, B. Fink s.n. (UPS!, holotype; MIN! NY! isotypes). Notes. – For a description and illustrations of this species see Knudsen et al. (2011). The species has a brown areolate to squamulose thallus and is widespread in North America and has a wide ecological amplitude and corresponding wide range of morphological variation. The two specimens cited below are pruinose, dark brown, and resemble specimens of the caesioalba-superfusa morphotype. The species is here newly reported for South America from Ecuador. Specimens examined. – ECUADOR. GALÁPAGOS PROV.: WESTERN/OESTE: Isabela, Volcán Alcedo, on crater rim NW of hut at highest point, humid zone, tortoise pasture with bare soil and scattered trees (Tournefortia rufo-sericea, Zanthoxylum fagara), 0°25'51”S 91°5'16”W, 1190 m, 5.iii.2006, on lava rock, A. Aptroot 64834 (CDS 31409). IMBABURA PROV.: Laguna Cuicocha, east edge, ca. 9 km W of town Cotacachi, 0°17’37”S 78°21’04”E, 3200-3500 m, 8.x.2000, on volcanic stones along a trail, Z. Palice 4473 (PRA). 2) Acarospora catamarcae H. Magn., Acta Horti Gothob. 17: 64. 1947. TYPE: ARGENTINA. CATAMARCA PROV.: ANDALGALÁ DEPT.: Cuesta de las Chileas, 21.ix.1945, on siliceous rock, M. Digilio-Crassi 2846 (UPS!, holotype) Notes. – For a description of this species see Magnusson (1947). This yellow species was described from Argentina and is only known from the holotype. It is a disappointing type specimen with a small amount of the taxon growing next to Acarospora boliviana H. Magn. Rather than dissecting the specimen, I had to rely on a stereo microscope examination coupled with a critical reading of the original description. In the future an epitype needs to be designated when a better specimen is found. The slightly glossy areoles and reddish brown to yellow apothecial discs of Acarospora catamarcae resemble A. rhabarbarina, which is common in Argentina (Knudsen 2007a; Knudsen et al. 2008). The specimen is small, the areoles possibly reduced by environmental stress, with fertile areoles approximately 0.5 mm in diameter, while the largest areoles are sterile and approximately 1 mm in diameter. I compared Acarospora catamarcae with A. rhabarbarina. The type of A. catamarcae differs significantly from A. rhabarbarina in having a much wider parathecium (80 µm vs. 10-30 µm). I have not observed this to be a variable character in A. rhabarbarina and neither did Magnusson (1929). Based on this difference, I tentatively accept A. catamarcae as a taxon distinct from A. rhabarbarina, however more specimens are needed for a detailed revision. Two other characters, hymenial height and width of cortex, differ from Acarospora rhabarbarina, but are not definitive in and of themselves due to the small size of the type. The hymenium of A. catamarcae is on the low end of the range of specimens of A. rhabarbarina I have observed so far (75-85 µm vs. 90-110 µm). Magnusson (1929) reported heights of 80-100 µm from his specimens (under the synonym A. bella (Nyl.) H. Magn.). However the differences between his observations and my own are not a significant. The width of the cortex in A. catamarcae is also below the lower limit of A. rhabarbarina, which varies in my measurements of specimens so far examined (35-40 µm vs. 50-130 µm). Magnusson (1929) also reported a wide range of cortical widths in A. rhabarbarina (50-120 µm). In large, well- developed areoles of A. rhabarbarina the eucortex can become very thick (50-130 µm). This wide range of cortical widths has also been observed in A. strigata (Nyl.) Jatta (Knudsen 2007a). In some species, such as A. rhabarbarina and A. strigata, as thalli grow larger new layers of hyphae are added to the cortex as well as the medulla and there is also usually a corresponding increase in the width of the algal layer. In other species of Acarospora increased size may only result in thickening of the algal layer and/or the medulla. More specimens of A. catamarcae are needed to determine if it always has a thinner cortex than A. rhabarbarina. Magnusson (1947) compared Acarospora catamarcae to A. regnelliana R. Sant., a species whose type I have not yet been able to examine. It may prove to be an earlier name for A. catamarcae. Magnusson (1947) also stated that A. catamarcae resembled a number of African species, none of which he to cited. This may indicate that an earlier name also exists amongst the species with African type specimens. 32 3) Acarospora rhabarbarina Hue, Morph. et Anat. 117. 1909. TYPE: CHILE: Quilmenco, C. Gay s.n. (PC[sheet 1]!, lectotype [designated by Knudsen et. al. (2008)]). Notes. – For descriptions and illustrations of this species see Knudsen (2007a) and Knudsen et. al. (2008). The yellow species has been reported from Argentina, Bolivia, Chile, and Peru (Knudsen 2007a, Knudsen et al. 2008). It is here reported new for Venezuela based on a collection by the Oberwinklers and Poelt. Specimen examined. – VENEZUELA. MERIDA: sine loc, 900 m, iii.1969. B. Oberwinkler et al. s.n. (GZU). 4) Acarospora sparsiuscula H. Magn., Acta Horti Gothob. 17: 65. 1947. TYPE: ARGENTINA. MENDOZA PROV.: SAN RAFAEL DEPT.: San Rafael, 2.ii.1946. L. Rossi 6797 (UPS!, holotype) Notes. – Those who do not study types would be surprised at the poor quality of some type specimens. The type of Acarospora sparsiuscula is exceptionally sparse, only two tiny areoles which are probably sterile. As with A. catamarcae above, I had to rely on a stereo microscope examination coupled with a critical reading of the original description. For a full description see Magnusson (1947). The specimens I examined were comprised of scattered brown areoles or squamules, without a dark underside, with an even algal layer, a hymenium about 100 μm tall, and a KC+ reddish cortex indicating the presence of gyrophoric/lecanoric acid. There are only three other species with gyrophoric/lecanoric acid currently known from South America, all known from one or a few collections. Acarospora obpallens (Nyl. ex Hasse) Zahlbr. differs in forming small round areoles or verrucae with small pits surrounding the apothecia. Acarospora subcastanae (Nyl.) Hue (syn. A. mendozana H. Magn. and A. sanguinascens Zahlbr.) has an areolate to squamulose continuous thallus that is subeffigurate and sometimes has a very weak KC+ reaction (this led Magnusson (1929) to describe A. mendozana as C-). Acarospora oligyrophorica Aptroot, the type specimen of which I have not yet examined, differs in having large ascospores like A. macrospora A. Massal. ex Bagl. Magnusson (1947) compared Acarospora sparsiuscula to A. sparsa H. Magn. which was described from North America. This comparison is not helpful however. The type of that species is lost (Knudsen et al.