Menjívar Cruz, J.E., R.M. Baldini, G. Davidse, and P.M. Peterson. 2021. El Salvador grasses: An updated catalogue and nomenclator. Phytoneuron 2021-22: 1–131. Published 20 April 2021. ISSN 2153 733 EL SALVADOR GRASSES: AN UPDATED CATALOGUE AND NOMENCLATOR JENNY ELIZABETH MENJÍVAR CRUZ Museo de Historia Natural de El Salvador Ministerio de Cultura de El Salvador San Salvador, El Salvador [email protected] RICCARDO M. BALDINI Centro Studi Erbario Tropicale Dipartimento di Biologia Università di Firenze Florence, Italy [email protected] GERRIT DAVIDSE Research Department Missouri Botanical Garden St. Louis, Missouri 63110 [email protected] PAUL M. PETERSON Department of Botany National Museum of Natural History Smithsonian Institution Washington, D.C. 20013-7012 [email protected] ABSTRACT An updated catalogue and nomenclator of the grasses in the Poaceae family is presented for El Salvador. The work is based on bibliographic and herbarium research and on recent collecting trips carried out by the first author in El Salvador between 2014−2017. The catalogue reports 371 species, 10 infraspecific names, and 381 total taxa. Herbarium vouchers, bibliographic reports, and distributions within El Salvador are reported for each accepted taxon. Synonyms are included in the list and these are all directed to the accepted name. A new combination, Rugoloa pilosa var. lancifolia (Griseb.) Baldini & Menjívar, comb. nov., is provided. RESUMEN Se presenta un catálogo y nomenclador actualizado de la familia Poaceae para El Salvador. El trabajo se basa en investigaciones bibliográficas de herbario, y en viajes de recolección recientes realizados por el primer autor en El Salvador entre 2014−2017. El catálogo informa 371 especies, 10 nombres infraespecíficos y 381 taxones en total. Los comprobantes de herbario, los informes bibliográficos y la distribución dentro de El Salvador se informan para cada taxón aceptado. Los sinónimos se incluyen en la lista y todos se dirigen al nombre aceptado. Una nueva combinación, Rugoloa pilosa var. lancifolia (Griseb.) Baldini y Menjívar, comb. nov., es aportada. Current knowledge on flora of El Salvador appears fragmentary and is relatively poorly reported (Menjívar & Cerén Lopéz 2017). If we exclude the first contributions of Standley & Caldéron (1925, 1941), a comprehensive taxonomic work for El Salvador does not exist, except for the dated “Flora Salvadoreña” published by Choussy (1926−1932). Most recent floristic contributions for plants of Central America are found in the Mesoamerican flora (Standley et al. 1946−1974), Costa Rica (Hammel et al. 2003−), Panama (Woodson et al. 1943−1981; Correa et al. 2004), Honduras (Sutherland Menjívar Cruz et al.: El Salvador grasses, updated catalogue and nomenclator 2 2008), and for Nicaragua (Stevens et al. 2001). Flora Mesoamericana (Davidse et al. 1994−) is the most detailed work on Central America, but still far from complete. Apart from Nicaragua (Stevens et al. 2001) and Costa Rica (Hammel et al. 2003−), we can argue that modern updated floras are still missing for the remaining countries of Central America. The most recent bibliographic review on partial studies of the flora of El Salvador is reported in Berendsohn et al. (2009, 2012) and Menjívar and Cerén Lopéz (2017). This work is specifically focused on the Poaceae, one of the most taxonomically and economically significant plant families in Mesoamerica. Apart from the older works on Central America and Caribbean areas (Hitchcock 1909, 1913, 1920, 1922, 1924, 1927, 1930, 1936; Hitchcock & Chase 1910, 1915, 1920; Standley 1937; Swallen 1936, 1943), and Flora Mesoamericana (Davidse et al. 1994), where citations for El Salvador are also reported, only two extensive regional works on Poaceae have been published until now for Mesoamerica: “Grasses of Guatemala” by Swallen (1955) in collaboration with F.A. MaClure for bamboos, the “Gramineae” by Pohl (1980) as a part of Flora Costaricensis edited by William Burger, and the contributions to Cuba by Catasús Guerra (2011, 2015). A recent checklist of the monocots, including 243 native and introduced grass species, for El Salvador was published by Berendsohn & Araniva de González (1991), here considered the basis from which we have started the present taxonomic and nomenclatural updated checklist. Plants of the World online (POWO 2021) lists 257 grass species for El Salvador. Our updated catalogue and nomenclator treating the El Salvadorian Poaceae is an extension of a broader project sponsored by MHES herbarium and supported by Secretaria de Cultura of the El Salvador. MATERIALS AND METHODS We compiled this checklist by consulting many literature sources available on Mesoamerican Poaceae, including the Caribbean area. We are aware that in many cases the distribution for a taxon is approximate, and often expressed by “Mexico to Panama”, or “USA to Panama,” as acknowledged in Berendsohn et al. (2009, 2012). For most species, herbarium specimens are cited to document the occurrence in El Salvador. However, we also include in our checklist a small number of species that historically have been reported in the literature. This work not only focuses on new records (nuevos registros), that often are not so “new” but also endeavors to contribute to understanding the biodiversity of grasses by including observations often taken from recent monographs that include phylogenetic analyses. We assembled the information from the bibliographic and digital herbarium resources (e.g., JACQ: <http://herbarium.univie.ac.at/database/search.php>; United States National Herbarium Catalogue <http://collections.nmnh.si.edu/search/botany/>, C.V. Starr Virtual Herbarium at New York Botanical Garden <http://sweetgum.nybg.org/science/vh/>, Field Museum Botany/database <http:// emuweb.fieldmuseum.org/botany/taxonomic.php?_ga=1.169204770.2036561786.1492616024>, and from important herbaria such as F, K, ITIC, LAGU, MHES, MO, NY, US, as reported in the literature (abbreviations follow Thiers 2019). Recently collected material from El Salvador (2014−2017) by the staff and associates of the Natural History Museum of El Salvador (MHES), the Jardin Botanico “La Laguna” in San Salvador (LAGU), and the Tropical herbarium of the University of Florence (FT) also was included. The distribution in El Salvador for most taxa is given by listing the Department where it occurs, all verified by the first author. Taxonomic and nomenclatural evaluation was made using THE PLANT LIST (http://www.theplantlist.org) and TROPICOS (http://www.tropicos.org). The general classification at subfamily and genus level follows Zuloaga et al. (2007), Teerawatananon et al. (2011), Vorontsova & Simon (2012), GPWG II (2012), Kellogg (2015), Soreng et al. (2015, 2017), and Washburn et al. (2015). In several occasions we have followed specific monographic works (see Literature Cited). The accepted name is always in bold type and native taxa have no attached symbol. Menjívar Cruz et al.: El Salvador grasses, updated catalogue and nomenclator 3 Symbols used here: * newly reported taxon ? dubious, to be confirmed # cultivated taxon § introduced taxon + endemic to El Salvador ** endemic genus to the New World RESULTS AND DISCUSSION For El Salvador we list 381 grass taxa (372 species) in 110 genera, of which 297 (288 species) are native. We also recognize: 19 newly reported taxa, 5 dubious, 1 endemic, 44 cultivated, 77 introduced and many of these (36) extensively cultivated, and 30 genera endemic to the New World. Paspalum is the largest genus with 47 species, followed by Digitaria (19), Eragrostis (16), Bouteloua (14), Cenchrus (14), Panicum (14), Aristida (11), Muhlenbergia (11), Lasiacis (10), and Setaria (10). Chusquea pittieri Hack. and C. simpliciflora Munro are included as occurring in El Salvador in the Plants of the World online (POWO 2021) but were not verified in our study. Clark (1994) indicates the former species is common in cloud forests and the latter species is found in tropical and lower montane forests. Other differences with the Plants of the World online and our list are referable to taxonomic rank where they include a specific subspecies or variety as occurring in El Salvador and we usually do not make a distinction. The impact of alien species from other tropical areas of the World, especially from Central and Southern Africa is remarkable and has made us aware of the need to monitor the grass flora in the future. El Salvador's territory has been subjected to severe anthropization and many native species, including grasses, have become rare if not completely extirpated. The expansion of open environments has favored a large component of non native grass species, these becoming very aggressive in the absence of natural competitors. Introductions from the Paleotropics, such as: Arthraxon hispidus, Cenchrus spp., Hyparrhenia bracteata, H. rufa, Hyperthelia dissoluta, Melinis minutiflora, M. repens, Setaria spp., and Urochloa spp., are now dominant in the open habitats throughout the country. Likewise, introductions from temperate genera, i.e., Bouteloua, Eragrostis, and Muhlenbergia, are now well represented in the flora. Pantropical taxa are also included in the grass flora, such as Aristida, Axonopus, Digitaria, Morronea, Panicum, Paspalum, and Rugoloa. Neotropical genera with centers of diversity in Mesoamerica, such as Chusquea, Lasiacis, Paspalum, Trachypogon, Zeugites, are still well represented and preserved in areas such as the Ahuachápan Mountains, Montecristo National Park (near Metapán),