Phytotaxa 282 (1): 001–018 http://www.mapress.com/j/pt/ Copyright © 2016 Magnolia Press Article PHYTOTAXA ISSN 1179-3155 (print edition) ISSN 1179-3163 (online edition) Accepted by Alexander Sennikov: 8 Oct. 2016; published: 26 Oct. 2016 http://dx.doi.org/10.11646/phytotaxa.282.1.1 1 The genus Stevia (Eupatorieae, Asteraceae) in Chile: a taxonomical and morphological analysis DIEGO G. GUTIÉRREZ 1 , MÉLICA MUÑOZ-SCHICK 2 , MARIANA A. GROSSI 3 , JUAN F. RODRÍGUEZ- CRAVERO 1 , VANEZZA MORALES 4 & ANDRÉS MOREIRA-MUÑOZ 5 1 División Plantas Vasculares, Museo Argentino de Ciencias Naturales (MACN-CONICET), Av. Angel Gallardo 470, C1405DJR Buenos Aires, Argentina. Reseracher CONICET; email: digutier@macn.gov.ar (corresponding author) 2 Museo Nacional de Historia Natural, Casilla 787, Santiago, Chile; email: melica4@gmail.com 3 División Plantas Vasculares, Museo de La Plata (FCNyM, UNLP), Paseo del Bosque s.n., B1900FWA La Plata, Argentina. Researcher CONICET; email: grossi@fcnym.unlp.edu.ar 4 Montecarmelo 53, Providencia, Santiago, Chile; email: vdmorale@gmail.com 5 Instituto de Geografía, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2241, Valparaíso, Chile; email: andres.moreira@pucv.cl Abstract A taxonomical study of the Chilean Stevia is herein presented since there is no agreement on current names and the number of species for Chile. A detailed morphological analysis of type and non-type specimens including new field observations was undertaken. In this work we recognized only one species of Stevia in Chile: S. philippiana. This species has a wide morphological variation mainly in leaf and pappus features. A lectotype of the name S. hyssopifolia was designated. Stevia hyssopifolia var. panulensis was regarded as a new synonym of S. philippiana. On the other hand, S. adenophora and S. chamaedrys were excluded from the Chilean flora. Finally, Porophyllym tarapacanum was excluded from the Tagetean ge- nus Porophyllum and included as a new synonym of S. philippiana, too. Key words: Compositae, Chilean flora, Porophyllum, Stevia philippiana, Taxonomy Introduction Asteraceae is the most diverse family of vascular plants in Chile, encompassing 20 tribes, 123 genera, and more than 830 species (Moreira-Muñoz & Muñoz-Schick 2007, Moreira-Muñoz et al. 2012) which represent almost a fifth of the Chilean flora. However, there are important gaps in the knowledge of identity and presence of several species and genera in this country, especially in areas geographically remote from central Chile (Moreira-Muñoz et al. 2016). Stevia Cavanilles (1797: 32) is the case of a genus taxonomically little known in Chile. This genus belongs to the subtribe Piqueriinae of the tribe Eupatorieae (Hind & Robinson 2007, Robinson et al. 2009). Stevia rebaudiana (Bertoni 1899: 35) Bertoni (1905: 3) (commonly “stevia”), from central Brazil and Paraguay, is the best known species which is used worldwide for food, industrial and medicinal properties (Brandle et al. 1998, Soejarto 2002, Salvador-Reyes et al. 2014). Stevia is characterized by its herbaceous to shrubby habit, usually opposite leaves, cylindrical involucre with five phyllaries, five florets with funnelform corollas, and pubescent 5-ribbed cypselae. The pappus is one of the most important features to identify the species of Stevia: short scales, bristles or a combination of bristles and scales. Commonly 1–2 cypselae in each capitulum have a reduced pappus (King & Robinson 1987, Hind & Robinson 2007), a phenomenon which is called heterocarpy (Robinson 1930). Cypselae with the normal type of pappus, usually four per capitulum, are called adelphocarps, and the fifth cypsela is the idiocarp (Robinson 1930). Stevia, which occurs in a wide variety of enviroments (e.g. wet or cloudy rainy forests, temperate-warm grasslands, dry enviroments, and high mountains), is distributed from southern United States in North America to northern Patagonia of Argentina in South America (King & Robinson 1987, Freire 2008, Freire & Ariza Espinar 2014). Particularly in Chile, this genus inhabits northern deserts belonging to the Desert Biogeographical Province (Cabrera & Willink 1980), which shows mainly both Tropical Pluviseasonal and Tropical Hyper-Desert bioclimates (Luebert & Pliscoff 2006).