Clarifying the occurrence and conservation status of Plantago dielsiana Pilg. and P.

: Problems in the original description of a species can have long-lasting consequences. This is the case of Plantago dielsiana and P. australis subsp. pretoana , two taxa referred to occur in Brazil by different authors. This work has the objective of clarifying the long-standing misunderstanding about the occurrence of these two taxa in Brazil. Additionally, we revise the distribution and assess the conservation status of P. australis subsp. pretoana , an endangered, rather poorly understood sub-species endemic to southeastern Brazil.

Plantago L. is a cosmopolitan genus of approximately 250 species, concentrated in temperate and high elevation tropical regions (Rahn 1996;Rønsted et al. 2002;Hefler et al. 2011;Meudt 2012). Plantago species are anemophilous herbs or rarely subshrubs, perennial or annual (Rønsted et al. 2002;Meudt 2012). A few of these species are adapted to anthropic environments (ruderal species), as a result becoming widely distributed (like P. major L. and P. lanceolata L.), but most species have restricted distribution and occur in more specialised environments (Rahn 1996;Mohsenzadeh et al. 2010;Segarra and Wood 2011;. Some Plantago species are endemic to small oceanic islands (Rahn 1996;Dunbar-Co et al. 2008;Meudt 2012). Because of its complex taxonomy (Ishikawa et al. 2009;Meudt 2011), it is not uncommon to find misidentified herbarium Plantago specimens, or even herbarium collections including specimens of different Plantago species. More drastic, however, is when such problems occur in the original description of a species: this is the case of P. dielsiana Pilg. (Pilger 1928).
Depending on the author, either Plantago dielsiana or P. australis Lam. subsp. pretoana Rahn (Rahn 1964) is referred to occur in Brazil (Pilger 1928(Pilger , 1937Rahn 1964Rahn , 1974Souza 2010;Kaehler 2014). A thorough literature review reveals a complicated taxonomic situation: in his description of P. australis subsp. pretoana, Rahn (1964) elected as holotype one of the paratypes of P. dielsiana [A.F.M. Glaziou 8897,C]. This taxonomic incident is here shown to be the cause of a long-standing misunderstanding about these two taxa.
To clarify the taxonomic situation and the distribution of these two taxa we revised the entire Plantago collections at herbaria C, EFC, FLOR, HBR, ICN, MBM and UPCB, and loan collections from RB. Additionally, we examined high-resolution images of collections from herbaria G, K, R, S and US.
Plantago dielsiana ( Figure 1) is a rather rare species, endemic to Pampean grasslands, restricted to southern Uruguay and eastern Buenos Aires province, eastern Argentina, at elevations no higher than 300 m above sea level (a.s.l.) (Rahn 1974(Rahn , 1995. It does not occur in Brazil, and therefore should be removed from the "List

ACKNOWLEDGEMENTS
Thanks are due to Olof Ryding, from herbarium C, for the scanning of the two collections included here, and to José Tadeu Weidlich Motta, from herbarium MBM, of Species of the Flora of Brazil" (Souza and Hassemer 2015).
Plantago australis subsp. pretoana (Figure 2) is a much rarer subspecies, exclusive to two small, considerable distinct areas: high elevation rocky bogs in the highest areas of Serra do Itatiaia, southeastern Brazil, at 2,000-2,600 m a.s.l., and wet grasslands around Lagoa Dourada, in Ponta Grossa, Paraná state, southern Brazil, at 790-840 m a.s.l. With the examination of the collections cited by Rahn (1974) Rahn (1996), updated by Rønsted et al. (2002).
Non-native species are marked with an asterisk.