IMA FUNGUS · 6(2): 373–469 (2015) doi:10.5598/imafungus.2015.06.02.09 Cercosporoid fungi (Mycosphaerellaceae) 4. Species on dicots ARTICLE (Acanthaceae to Amaranthaceae) Uwe Braun1, Pedro W. Crous2, and Chiharu Nakashima3 1Martin-Luther-Universitt, Institut für Biologie, Bereich Geobotanik und Botanischer Garten, Herbarium, Neuwerk 21, 06099 Halle (Saale), Germany; corresponding author e-mail: [email protected] 2CBS-KNAW, Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands 3Graduate School of Bioresources, Mie University, 1577 Kurima-machiya, Tsu, Mie 514-8507, Japan Abstract: The present paper continues a series of comprehensive taxonomic treatments of cercosporoid fungi Key words: (formerly Cercospora s. lat.), belonging to the Mycosphaerellaceae (Ascomycota). The fourth contribution of this Ascomycota series initiates treatments of cercosporoid fungi on dicots and comprises species occurring on hosts belonging the Cercospora s. lat. the families Acanthaceae, Actinidiaceae, Adoxaceae, Aizoaceae, Altingiaceae, and Amaranthaceae. The species hyphomycetes are described and illustrated in alphabetical order under the particular cercosporoid genera, supplemented by keys taxonomy to the species concerned. A detailed introduction, a survey of currently recognised cercosporoid genera, a key to the genera concerned, and a discussion of taxonomically relevant characters were published in the rst part of this series. The following taxonomic novelties are introduced: Cercospora blepharidicola nom. nov., C. celosiigena sp. nov., C. justiciae-adhatodae sp. nov., C. justiciigena nom. nov., C. sambucicola nom. nov., C. thunbergiigena nom. nov., Cercosporella pseudachyranthis comb. nov., Pseudocercospora cyathulae comb. nov., P. depazeoides comb. nov., P. varia var. viburni-sargentii var. nov., P. viburnicola sp. nov., P. viburni-erosi sp. nov., and P. viburni-nudi sp. nov. Article info: Submitted: 26 September 2015; Accepted: 29 October 2015; Published: 10 November 2015. INTRODUCTION follows the principles circumscribed in part 1 (Braun et al. 2013). True cercosporoid fungi belong to Mycosphaerellaceae (Capnodiales, Ascomycota) and comprise a very large group of plant pathogenic, leaf-spotting, economically MATERIALS AND METHODS relevant species that cause diseases on a wide range of hosts, including numerous cultivated plants. In spite of the The present work is a compilation based on our papers enormous relevance of this fungal group, there is no modern and unpublished data, as well as the global literature. comprehensive treatment of Cercospora and allied genera, Details of methods are given in the papers cited under and the only monograph published by Chupp (1954) is references. As far as new examinations are concerned, seriously outdated. Therefore, a monographic series with fungal structures have been examined by standard methods treatments of cercosporoid fungi based on host families was of light microscopy, using an Olympus BX50 microscope, initiated (Braun et al. 2013) with the aim of working towards with distilled water and lactic acid as media, but without any a comprehensive monograph of this generic complex. staining. If possible, measurements of 30 conidia and other So far three contributions have been published: part one structures have been made at a magnication of ×1000. dealing with cercosporoid fungi on other fungi (mycophylic All illustrations have been prepared by UB. The following taxa), on ferns as well as gymnosperms (Braun et al. 2013); abbreviations are used: author names follow Brummit & part two dedicated to species on monocots, excluding true Powell (1992), journals Bridson (2004a, b), and exsiccatae grasses (Braun et al. 2014); and part three with a treatment http://www.botanischestaatssammlung.de/DatabaseClient/ of cercosporoids on hosts of Poaceae (Braun et al. 2015). IndExs/index.jsp (IndExs – Index of Exsiccatae). Taxonomy General chapters with generic descriptions and keys to and nomenclature of plant families, genera and species accepted genera are included in the rst part. The present are based on the “Angiosperm Phylogeny Website” (http:// contribution is the rst part devoted to cercosporoid fungi www.mobot.org/mobot/research/apweb/), Tropicos database on dicots, encompassing species on hosts of the families (http://www.tropicos.org/), and The Plant List (http://www. Acanthaceae, Actinidiaceae, Adoxaceae, Aizoaceae, theplantlist.org). Altingiaceae, and Amaranthaceae. The structure of part 4 © 2015 International Mycological Association You are free to share - to copy, distribute and transmit the work, under the following conditions: Attribution: You must attribute the work in the manner specied by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). Non-commercial: You may not use this work for commercial purposes. No derivative works: You may not alter, transform, or build upon this work. For any reuse or distribution, you must make clear to others the license terms of this work, which can be found at http://creativecommons.org/licenses/by-nc-nd/3.0/legalcode. Any of the above conditions can be waived if you get permission from the copyright holder. Nothing in this license impairs or restricts the author’s moral rights. VOLUME 6 · NO. 2 373 Braun et al. TAXONOMIC TREATMENT Cercosporoid species on dicots s. lat. (Acanthaceae to Amaranthaceae) Acanthaceae ARTICLE Cercospora Key to Cercospora species on Acanthaceae 1 Conidia in chains, 8–40 × 2–3 μm, (0–)1–3(–4)-septate, hyaline; on Justicia adhatoda [Adhatoda vasica] .............................................................................................................................. Cercospora justiciae-adhatodae Conidia formed singly ...................................................................................................................................................... 2 2 (1) Stromata large, 20–85 μm; conidiophores short, 10–40 × 3–5 μm, 0–4-septate; conidia short, acicular-subcylindrical, 20–50 × 2–4 μm, 0–5-septate ................................................................... C. balaghatensis Stromata lacking or smaller, 10–30 μm diam; and/or conidiophores much longer, 10–500 μm, pluriseptate throughout; conidia longer, 15–360 μm, pluriseptate ........................................................................... 3 3 (2) Conidia obclavate-cylindrical with obconically truncate base .......................................................................................... 4 Conidia consistently acicular, base truncate, or at least longer conidia acicular, mixed with shorter obclavate-cylindrical conidia ...................................................................................................... 6 4 (3) Conidiophores short, 10–40 × 2.5–5 μm, 0–1-septate; conidia 25–80 μm long; on Justicia spicigera, Central America (Guatemala) .......................................................................................................... C. jacobiniicola Conidiophores longer, about 30–185 μm, with more than two septa; conidia longer, about 20–170 μm ........................ 5 5 (4) Stromata 30–50 μm diam; conidiophores long and aseptate, 35–120 × 3–6 μm; on Justicia betonica, Asia (India) ....................................................................................................... C. justiciigena Stromata lacking or very small, < 25 μm diam; length of the conidiophores similar, but 1–6-septate; on Lepidagathis spp. ...................................................................................................................... C. lepidagathidis 6 (3) Conidia acicular to obclavate-cylindrical, base truncate to obconically truncate ............................................................. 7 Conidia consistently acicular, base truncate ................................................................................................................. 10 7 (6) Conidiophores relatively short, 10–30(–70) μm; stromata 10–70 μm diam; on Acanthus spp. ........................ C. acanthi Conidiophores longer, 25–155 μm; stromata lacking or small, 10–30 μm; on other hosts ............................................. 8 8 (7) Conidia narrow, 30–150 × 2–4 μm, average < 3 μm wide; on Andrographis spp. .............................. C. andrographidis Conidia wider, 3–5 μm, average > 3 μm; on other hosts ................................................................................................ 9 9 (8) Conidiophores to 195 μm long; on Justicia spp. ........................................................................................ C. justiciicola Conidiophores much shorter, to 62.5 μm; on Crossandra spp. ............................................................... C. crossandrae 10 (6) Stromata well-developed, 10–70 μm diam; conidiophores short, 10–40(–7) μm; on Acanthus sp. ................. C. acanthi Stromata lacking or small, about 10–45 μm diam; and/or conidiophores much longer, at least partly longer than 50 μm; on other hosts .................................................................................................... 11 11 (10) Conidiophores 40–310 × 4–8.5 μm; conidia rather broad, 40–360 × 3–8 μm; on Thunbergia spp. ....... C. thunbergiana Conidiophores and conidia narrower; conidia about 1.5–5 μm wide; on other hosts or if on Thubergia conidia only 2–3 μm wide ............................................................................................................. 12 12 (11) Conidia (2–)2.5–5.5(–6)