A new species of Solanum named for Jeanne Baret, an overlooked contributor to the history of botany

Abstract We describe Solanum baretiae sp. nov., a new species of Solanum section Anarrhichomenum, named in honor of Jeanne Baret, who sailed as the assistant to botanist Philibert Commerson on Louis Antoine de Bougainville’s global circumnavigation (1766–1769). The species is similar to Solanum chimborazense, but differs in having larger flowers, more flowers per inflorescence, and different patterns of pubescence on the filaments (pubescent adaxially and glabrous abaxially) and style (papillose to sparsely pubescent). A description, illustration, photos, and comparisons to similar species are included. Also included is a preliminary conservation assessment, along with a brief account of the important role played by Baret during the expedition. The new species appears to be restricted to the Amotape-Huancabamba zone, an area of southern Ecuador and northern Peru known for its exceptional biodiversity.


Introduction
Botanizing in the 15 th -19 th centuries, when naturalists traveled on board ships that sailed to little known parts of the world, must have been truly extraordinary. Th e hardships endured on these voyages are unfathomable to fi eld biologists these days and, although many of the plant families seen on voyages across the seas were familiar to European naturalists, many of the genera and nearly all of the species encountered and collected were new to Western science. Discovery on such a grand scale is no longer a reality, but detailed focus on groups of plants reveals that a great deal of diversity remains to be uncovered. Fieldwork associated with the PBI (Planetary Biodiversity Inventory) Solanum project has resulted in the collection or description of nearly 50 new species of Solanum L. to date (recent examples include Tepe and Bohs 2009, Stern and Bohs 2009, 2010, Knapp 2010a, b, Vorontsova and Mbago 2010, including the new species of Solanum sect. Anarrhichomenum Bitter from southern Ecuador and northern Peru described here. Solanum, with an estimated 1500 species, is not only one of the world's largest genera of plants (Frodin 2004), but, considering that it includes the tomato (S. lycopersicum L.), potato (S. tuberosum L.), and eggplant (S. melongena L.), it is also one of the most economically important. Th e PBI: Solanum project is an eff ort to provide a worldwide revision of Solanum and make data freely available online at www.solanaceaesource.org; a taxonomic revision of Solanum section Anarrhichomenum forms part of this project. Th e section encompasses a group of 10 to 20 viny species found primarily in mountainous habitats from Mexico to Bolivia (Correll 1962, Nee et al. 2006. It is closely related to the pepino (S. muricatum Ait.) and the clade that contains the tomato and potato (Spooner et al. 1993), and is part of the larger Potato clade sensu Bohs (2005) and Weese and Bohs (2007). Members of this section can be distinguished by fruits that mature to red or orange, seeds with a prominent wing in most species, and the presence of a single or strongly anisophyllous pair of pseudostipules at each node. Pseudostipules, which are leaf-like, often crescent-shaped appendages located near the point of petiole insertion, are present in several groups within Solanum and other genera of Solanaceae. Th ey do not appear to be part of the leaves that they accompany, but are instead interpreted to be the fi rst leaf or leaves of an arrested axillary shoot (for further discussion see Spooner et al. 2004, Peralta et al. 2008. Th e leaves of many species are also punctate with whitish deposits of crystal sand ("sand punctate" hereafter). Cells containing deposits like these are found in several groups within Solanum (Whalen et al. 1986, Bohs 1990, Knapp 1992 and in other groups of angiosperms (Metcalfe and Chalk 1983). Correll (1962) provided a revision of Solanum section Anarrhichomenum [as Solanum section Tuberarium (Dunal) Bitter subsection Basarthrum Bitter series Appendiculata Rydb.] in his monograph of the potatoes s.l. Subsequent studies have clarifi ed the limits of the section as well as many of its component species using a variety of techniques, including morphological examination of the plants, pubescence, pollen, and chromosomes (Anderson 1979a, 1979b, Anderson and Gensel 1976, Anderson and Levine 1982, Seithe and Anderson 1982, Levine and Anderson 1986, Bernardello and Anderson 1990, Anderson et al. 1999, biosystematic studies (Mione and Anderson 1992), analyses of foliar fl avonoids (Anderson et al. 1987), and, most recently, molecular techniques (Spooner et al. 1993, Anderson andJansen 1994). Despite this attention, other species of Solanum section Anarrhichomenum remain poorly understood and new species exist. Th e section is currently under revision by the fi rst author, who is attempting to update Correll's (1962) treatment. Th is study will incorporate results from the studies mentioned above, specimens from extensive collecting in recent decades, and data derived from additional morphological and molecular studies. During this work, the following new species was recognized.

Solanum baretiae
Distribution and ecology. Solanum baretiae is apparently endemic to the Amotape-Huancabamba zone of southern Ecuador and northern Peru and grows in the understory of montane forests and disturbed roadside and pasture vegetation, 1900-3000 m in elevation. Th e areas where S. baretiae has been collected are seasonally dry.
Phenology. Flowering specimens have been collected from Jun-Aug and Oct; fruiting specimens have been collected in May-Jun.
Etymology. Solanum baretiae is named in honor of the botanist Jeanne Baret, the fi rst woman to circumnavigate the earth (see below).
Preliminary conservation status. According to the IUCN Red List Categories (IUCN 2011), S. baretiae is classifi ed as Data Defi cient (DD). Although S. baretiae occurs over a broad geographic range (> 60,000 km 2 ), it has been collected at fewer than 10 localities (localities within a few kilometers of each other have been grouped for this assessment) and from a narrow elevational band within its range. Th e relatively small number of collections of this species suggests that it is rare in the habitats where it occurs. Furthermore, these localities are near expanding population centers and habitats in these areas are highly fragmented and degraded. Nevertheless, S. baretiae seems to be well suited to habitat change caused by human activities, since EJT and LB observed thriving populations along roadsides and among shrubs between the town of Guzmango (Dept. Cajamarca, Peru) and the cultivated and pasture lands that surround the town. Further data regarding the distribution and abundance of S. baretiae are needed before we can make a more solid assessment of its conservation status. Discussion. Solanum baretiae is a striking species with its relatively large, pentagonal corollas in shades of violet, yellow, or white (Fig. 2B), and its soft-pubescent leaves that range from simple to 7-foliolate. Specimens of S. baretiae have been previously identifi ed as the Ecuadorian S. chimborazense Bitter, from which it diff ers by its larger corollas (0.8-1.5 cm in S. baretiae vs. < 1 cm in diameter in S. chimborazense), styles that are papillose or only sparsely pubescent (vs. densely pubescent with long trichomes in S. chimborazense), more fl owers per infl orescence (1-8 in S. baretiae vs. mostly 1, but up to 3 in S. chimborazense), and fi laments that are pubescent adaxially, but glabrous abaxially (vs. evenly pubescent on all surfaces in S. chimborazense). Solanum baretiae is sympatric with the exceedingly rare S. chachapoyasense Bitter but the latter species has stellate corollas (vs. pentagonal in S. baretiae), long fi laments (3-3.5 mm in S. chachapoyasense vs. 0.5-1.5 mm in S. baretiae), and strictly simple leaves (vs. simple to 7-foliolate in S. baretiae). Solanum baretiae is also sympatric with several species of Solanum section Basarthrum (Bitter) Bitter, which can be scandent shrubs with compound leaves and somewhat similar fl owers. Th ese species, however, can easily be diff erentiated by the distinctive two-celled "bayonet" trichomes that characterize Solanum section Basarthrum (Seithe and Anderson 1982).
Th e Andean species of Solanum sect. Anarrhichomenum are typically found in midto high-elevation cloud forest habitats that are moist throughout the year. Solanum baretiae appears to be an exception to this rule, however, as it occurs in forests and disturbed areas on the western slopes of the Andes which, in the latitudes of the Huancabamba-Amotape zone, experience a marked dry season.
As mentioned above, the number of leafl ets in this species is highly variable, with the leaves ranging from simple to compound with seven leafl ets. Seedlings and young vegetative shoots typically have compound leaves with fi ve leafl ets, whereas the number of leafl ets on fertile shoots is much more variable. In general, the number of leafl ets, along with the size of the lateral leafl ets, decreases along the length of fertile shoots, and the leaves in the proximity of the fl owers and fruits are, in many cases, simple or have only one or two tiny lateral leafl ets. Th e number of leafl ets is variable in many species of Solanum sect. Anarrhichomenum, but the range of variability seen in S. baretiae is shared only with that of S. sodiroi Bitter (Anderson et al. 1999).
Th is species in named in honor of Jeanne Baret (1740-1807), an unwitting explorer who risked life and limb for love of botany and, in doing so, became the fi rst woman to circumnavigate the world (Ridley 2010).
Jeanne Baret sailed on the ship L'Étoile in 1766 and embarked on the fi rst French circumnavigation of the globe under the command of Louis Antoine de Bougainville (1729-1811) as assistant to the botanist Philibert Commerson (1727-1773). Since French naval regulations prohibited women being on board ship, Baret disguised herself as a man to join the expedition, and continued to wear men's clothes during her time on the ship. Baret was Commerson's lover, but was also an accomplished botanist in her own right and evidence suggests that she made some of the expedition's most notable collections, including the showiest, most enduring botanical specimen from the expedition: the vine that would be named in honor of its commander, Bougainvillea Comm. ex Juss.
Commerson and Baret (though uncredited) amassed over six thousand specimens that are incorporated into the French National Herbarium at the Muséum National d'Histoire Naturelle. In the course of the expedition and the years after its successful completion, over seventy species would be named in honor of Com-merson using the specifi c epithet commersonii. Expedition records show that Commerson was frequently unable to collect specimens in the fi eld because of his health issues (Vivès 1766(Vivès -1769 and, at these times, Baret took the part of the expedition's chief botanist. Yet, today, despite the important role she played, not a single species is named after her. Commerson's notes reveal that he intended to name a Malagasy genus Baretia (MS 887 of the Commerson archive in the Muséum National d'Histoire Naturelle), but it was never published (the species concerned are now placed in Turraea of the Meliaceae). Th e fact that individual plants of this genus that Commerson collected with Baret have leaves that are highly variable in shape perhaps struck him as a neat refl ection of the multi-faceted companion who united seemingly contradictory qualities (Monnier et al. 1993): a woman dressed as a man, a female botanist in a male-dominated fi eld, and a working class woman who had traveled farther than most aristocrats. Given the importance of her work and the singular nature of her achievements, Baret has clearly made a suffi cient contribution to the fi eld to deserve a species named after her. Following Commerson's example, we believe that this new species of Solanum, with its highly variable leaves, is a fi tting tribute to Baret.