J. Fungi 2023, 9, 246. https://doi.org/10.3390/jof9020246 www.mdpi.com/journal/jof Article The Lichen Genus Sticta (Lobariaceae, Peltigerales) in East African Montane Ecosystems Ulla Kaasalainen 1,2, *, Paul M. Kirika 3 , Neduvoto P. Mollel 4 , Andreas Hemp 5 and Jouko Rikkinen 1,6 1 Finnish Museum of Natural History, University of Helsinki, P.O. Box 7, 00014 Helsinki, Finland 2 Department of Geobiology, University of Göttingen, Goldschmidtstraße 3, 37077 Göttingen, Germany 3 National Museums of Kenya, East African Herbarium, Museum Hill Road, P.O. Box 45166, Nairobi 00100, Kenya 4 National Herbarium, Tropical Pesticides Research Institute, P.O. Box 3024, Arusha 23201, Tanzania 5 Department of Plant Systematics, University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany 6 Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, 00014 Helsinki, Finland * Correspondence: ulla.kaasalainen@helsinki.fi Abstract: The lichen flora of Africa is still poorly known. In many parts of the tropics, recent studies utilizing DNA methods have revealed extraordinary diversity among various groups of lichenized fungi, including the genus Sticta. In this study, East African Sticta species and their ecology are re- viewed using the genetic barcoding marker nuITS and morphological characters. The studied re- gions represent montane areas in Kenya and Tanzania, including the Taita Hills and Mt. Kiliman- jaro, which belong to the Eastern Afromontane biodiversity hotspot. Altogether 14 Sticta species are confirmed from the study region, including the previously reported S. fuliginosa, S. sublimbata, S. tomentosa, and S. umbilicariiformis. Sticta andina, S. ciliata, S. duplolimbata, S. fuliginoides, and S. mar- ginalis are reported as new to Kenya and/or Tanzania. Sticta afromontana, S. aspratilis, S. cellulosa, S. cyanocaperata, and S. munda, are described as new to science. The abundance of new diversity de- tected and the number of taxa represented by only few specimens show that more comprehensive sampling of the region may be needed to reveal the true diversity of Sticta in East Africa. More generally, our results highlight the need for further taxonomic studies of lichenized fungi in the region. Keywords: Mt. Kilimanjaro; Taita Hills; Mt. Kasigau; Eastern Arc; Mt. Elgon; Eastern Afromontane biodiversity hotspot; nuITS; lichenized fungi; Ascomycota; molecular phylogeny 1. Introduction Tropical mountains, and especially their forests, are hot spots of biodiversity and endemism [1–4]. In East Africa, montane regions, such as the ancient Eastern Arc Moun- tains which range from southern Tanzania to Kenya, and the much younger volcanic mountains, such as Mt. Kilimanjaro in Tanzania and Mt. Elgon at the border of Kenya and Uganda, are surrounded by vast stretches of arid woodlands and savannas [5,6]. Still, es- pecially the humid upper windward slopes of these mountains have provided refuge for the montane rainforests already for millions of years [6,7]. During this time, climatic in- duced fluctuations in the areal extent and isolation of moist montane forests have gener- ated remarkably high levels of diversity and local endemism [1,3,6,8,9] in what is now known as the Eastern Afromontane biodiversity hotspot [10,11]. The lichen flora of Africa is poorly known and is still largely based on information collected during the 20th century [12]. So far, only few groups of parmelioid and cy- anolichens have been studied in any detail, and especially the more recent application of DNA methods has revealed high levels of previously unknown diversity [13–18]. Sticta Citation: Kaasalainen, U.; Kirika, P.M.; Mollel, N.P.; Hemp, A.; Rikkinen, J. The Lichen Genus Sticta (Lobariaceae, Peltigerales) in East African Montane Ecosystems. J. Fungi 2023, 9, 246. https://doi.org/10.3390/jof9020246 Academic Editor: Silke Werth Received: 30 December 2022 Revised: 3 February 2023 Accepted: 6 February 2023 Published: 12 February 2023 Copyright: © 2023 by the authors. Li- censee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and con- ditions of the Creative Commons At- tribution (CC BY) license (https://cre- ativecommons.org/licenses/by/4.0/).