Two new species of Athenaea Sendtn. (Solanaceae) from the Atlantic forests of south-eastern Brazil

Abstract Two new species of Athenaea Sendtn. (Solanaceae) from the Brazilian Atlantic Forest are described and illustrated. Athenaea altoserranae I.M.C. Rodrigues & Stehmann, sp. nov. from the Serra do Mar range, in São Paulo State and Athenaea hunzikeriana I.M.C. Rodrigues & Stehmann, sp. nov. from a restricted area in the north-eastern region of Minas Gerais State and the southern part of Bahia State. Both species have brown to purple-brown or purple mature fruits, a character not found in other species of Athenaea. Descriptions, illustrations, complete specimen citations and maps of both species are provided. A dichotomous key to all species of Athenaea is also presented.

CORD, ESA, IAC, MBM, MBML, MO, NY, R, RB, SP and SPF; and specimens accessed as digital images via INCT Herbário Virtual (http://inct.splink.org.br) and Reflora -Herbário Virtual (http://reflora.jbrj.gov.br/reflora/herbarioVirtual/) databases were conducted to confirm the novelty of the species described here. All barcode and accession numbers, as well as label details for the new species, are presented in Suppl. material 2 and on the Natural History Museum Data Portal (https://doi.org/10.5519/ zc80n093). In the field, fresh flowers were fixed in alcohol to permit detailed descriptions and illustrations using dissection and compound microscopy.
We calculated the Extent of Occurrence (EOO) and Area of Occupancy (AOO) using GeoCat (http://geocat.kew.org) calibrated with the standard 2 km 2 cell width for the AOO measurement. A preliminary conservation status was assigned using the IUCN (2019) criteria implemented in GeoCat analyses (Bachman et al. 2011) combined with our field knowledge of habitats and threats to the Brazilian Atlantic forests.
Etymology. The specific epithet is a reference to "Alto da Serra", located in the District of Paranapiacaba, Municipality of Santo André, São Paulo State, where the species, including the type gathering, has been collected since 1917. This area was the first biological station in South America, established in 1909 by Hermann Friedrich Albrecht von Ihering. In 1938, under the administration of the Instituto de Botânica de São Paulo, the name was changed to Reserva Biológica do Alto da Serra de Paranapiacaba (Marcolin 2009).
Phenology. Athenaea altoserranae flowers and fruits from August to March. Distribution and habitat. Athenaea altoserranae is endemic to Brazil and restricted to the edges of the plateau of the Serra do Mar mountain range in São Paulo State.
It grows in the wet Atlantic rain forest (Mata Atlântica), often in clearings and along trails or other open places from 714 to 1,100 m elevation.
Preliminary conservation assessment (IUCN 2019). Endangered (EN). EOO 1,240.9 km 2 (EN); AOO 48 km 2 (EN). This species occurs in the plateau of Serra do Mar and near the coast in the Municipality of Cananéia, São Paulo State, an area originally totally covered by Atlantic rain forest. The restricted range, coupled with the fragmented habitat, suggests a preliminary assessment of Endangered B1a and B2a, b (ii and iii).
Discussion. Specimens of Athenaea altoserranae have been variously identified in herbaria as Aureliana fasciculata (Vell.) Sendtn., Aureliana fasciculata var. longifolia (Sendtn.) Hunz. and Barboza or Aureliana glomuliflora Sendtn. -all currently recognised as synonyms of the widespread glabrous species Athenaea fasciculata (Vell.) I.M.C.Rodrigues & Stehmann. Athenaea fasciculata is the most widespread species of the genus and is distributed along the Atlantic rain forest from southern to northeastern Brazil, but also occurs south to Paraguay and Argentina and west to eastern Peru and Bolivia (see Rodrigues et al. 2019). Athenaea altoserranae is sympatric with A. fasciculata, A. cuspidata, A. pogogena, A. picta, A. sellowiana and A. wettsteiniana. Hunziker and Barboza (1990) recognised three infraspecific taxa within their circumscription of Aureliana fasciculata (A. fasciculata var. fasciculata, A. fasciculata var. longifolia Sendtn. and A. fasciculata var. tomentella Hunz. & Barboza). They included material of Athenaea altoserranae in their circumscription of var. longifolia along with other specimens collected in Bahia and the border of São Paulo with Paraná (SP/PR); the only original material we have seen for var. longifolia was destroyed in the bombing of the Berlin herbarium and no duplicates have been found, but a photograph (F neg. 2880, of an un-numbered F. Sellow collection from "Brasilia australiore" annotated "Bassovia glomuliflora Dun. β longifolium") corresponds to A. fasciculata s.l. and not to A. altoserranae (Rodrigues et al. 2019). Although all of the specimens included in var. longifolia by Hunziker and Barboza (1990) share completely glabrous leaves, the plants from Bahia and from the São Paulo/Paraná border have small flowers, long-obovate leaves with a cuspidate apex and longer petioles, thus distinguishing them from the plants here recognised as A. altoserranae. We currently include these plants from Bahia and from the São Paulo/Paraná border in our circumscription of A. fasciculata s.l.
Preliminary conservation assessment (IUCN 2019). Data Deficient (DD). Just two populations of A. hunzikeriana are known, one growing in a private reserve (RPPN Fazenda Duas Barras), in the Municipality of Santa Maria do Salto, Minas Gerais and another in Fazenda Farofa in the Municipality of Boa Nova, Bahia. Although the locality in Bahia is well-protected, the extremely restricted range indicates the species is of some conservation concern.
Discussion. Athenaea hunzikeriana is easily recognised by its purple, eglandularpubescent mature fruits on erect or spreading pedicels, its large seeds and the distinctive inflorescences with a short but persistent axis. Other species of Athenaea have axillary fascicles, with no rhachis along which pedicel scars can be observed. This species is morphologically similar to and sympatric with A. pogogena, with which it shares almost all flower characteristics, but can be distinguished by its subglobose (versus conic or ovoid) berry and leaf pubescence of mostly eglandular trichomes with sparse minute glandular trichomes, rather than densely glandular pubescent leaves. Athenaea hunzikeriana is also vegetatively similar to A. anonacea Sendtn. and A. martiana Sendtn. in having pubescent leaves but is differentiated from both those species by its pubescent fruit and non-accrescent fruiting calyx. It is also sympatric with A. fasciculata but differs from that species in its conspicuous pubescence (A. fasciculata is glabrous, see discussion of A. altoserranae above). Additional

Dichotomous key to the species of Athenaea
All of the species in this key occur in Brazil, their distribution can be found in Rodrigues et al. (2019); A. fasciculata is the only species that occurs outside of Brazil.