A new species of Eremitis Döll (Poaceae, Bambusoideae) from the Baixo Jequitinhonha region, an area of extreme importance for the conservation of the flora of Minas Gerais, Brazil

Eremitis is one of the three genera of the subtribe Parianinae (Poaceae, Bambusoideae, Olyreae) and is restricted to the Atlantic Forest in eastern Brazil. Eremitis aemula , herein described and illustrated, is microendemic to the Alto Cariri State Park, located in the Baixo Jequitinhonha region, an area considered to be extremely important for conservation of the flora in the state of Minas Gerais. This new species is morphologically similar to Eremitis jardimii and E. robusta . However, E. aemula is differentiated from both species mainly by its longer decumbent culms (47–50 cm long vs. 22–25 cm and (15–)25–28 cm, respectively) with shorter inflorescences (4.5–5 cm long vs. 5.5–6 cm and 6–6.5 cm, respectively), and by its leaf blades with rounded base ( vs. attenuate in E. jardimii and E. robusta ). The total number of bamboos in Minas Gerais thereby rises to 79 species with 16 endemic to the state, reinforcing the fact that the Baixo Jequitinhonha is of extreme importance to the conservation of the Minas Gerais flora.


Introduction
The Brazilian state of Minas Gerais occupies an area of 588,528 km 2 , partitioned into 853 municipalities (IBGE 2020).Minas Gerais is characterized by a set of extremely variable abiotic factors such as relief, climate, soil, and water resources (Drummond et al. 2005).Such different geomorphological conditions contribute to the presence of several distinct vegetation types and an extraordinary floristic richness (Drummond et al. 2005).According to Flora do Brasil 2020 (2020), Minas Gerais is the richest Brazilian state in angiosperm diversity, with 12,153 species.This diversity is also observed in the bamboo group (Poaceae, Bambusoideae).With 78 species, of which 15 are endemic, Minas Gerais is the second most diverse Brazilian state in bamboo species, in addition to Bahia (91 species, 37 endemic) and Espírito Santo (51 species, eight endemic) (Flora do Brasil 2020 2020).
Eremitis is one of the three monophyletic lineages of herbaceous bamboos that compose the subtribe Parianinae (Ferreira et al. 2019).Along with Parianella, the genus has a distribution restricted to the Atlantic Forest of eastern Brazil (Ferreira et al. 2013a;2019).The other recognized genus of this subtribe, Pariana, is more widely distributed throughout the Amazon Basin and into Central America (Hollowell 1987;Judziewicz et al. 1999;Clark & Oliveira 2018;Ferreira et al. 2019).In addition to molecular data, four morphological synapomorphies define Parianinae: spiciform inflorescences, spikelets in whorls, articulated inflorescence axes, and staminate spikelets with glumes (Ferreira et al. 2019).The monophyly of Eremitis is supported by molecular data and five morphological synapomorphies: truly underground culms, sympodial inflorescences on leafy culms, gynecandrous and staminate spikelet whorls in the same inflorescence, staminate spikelet pedicels elongated and laminar only in the terminal whorl, and pubescent styles (Ferreira et al. 2019).
Currently, Eremitis encompasses 16 species (Ferreira et al. 2013b;2016;2019;2020a;b;c;d;2021a;b).During the taxonomic revision of the genus, a new species from Minas Gerais was found, which is morphologically similar to Eremitis jardimii and E. robusta (both from Bahia state).The new species described here increases the number of bamboo species in Minas Gerais to 79 species (16 endemic).This reinforces the fact that this state is a critical area for bamboo diversity (Ferreira et al. 2020a).In the present study, we provide a morphological description, illustrations, a distribution map, and notes on habitat and conservation status of the new species, as well as a morphological comparison with similar Eremitis species.

Materials and methods
Morphological investigation of the studied species was based on herbarium specimens (from ALCB, BHCB, CEPEC, CVRD, ESA, GUA, HUEFS, HUFU, IAN, INPA, ISC, K, LE, MBM, MBML, MG, MO, NY, P, PEUFR, R, RB, RBR, SP, SPF, UEC, UESC, US, and VIC herbaria; acronyms according to Thiers 2020, continuously updated), type collections, and fieldwork throughout the geographical distribution of the genus.The morphological terminology follows Hollowell (1987) and Ferreira et al. (2013b).In addition, web-based resources such as Tropicos (https://www.tropicos.org/), SpeciesLink system (https://specieslink.net/), and Reflora -Virtual Herbarium (https://floradobrasil.jbrj.gov.br/reflora) were accessed in order to check additional specimens, and update the geographical distribution of the genus.The conservation status was proposed following the recommendations of IUCN Red List categories and criteria, version 14 (IUCN Standards and Petitions Committee 2019).The area of occupancy (AOO) was calculated using the GeoCAT tool (Bachman et al. 2011), with 2 × 2 km grid cells.Since the new species is only known from one locality so far, it was not possible to calculate its extent of occurrence (EOO).Maps were elaborated using the website SimpleMappr (Shorthouse 2010) and the software ArcMap (ESRI 2008).Geographical coordinates were obtained during the fieldwork and from collection details indicated in the labels of herbarium specimens.

Result and discussion
Taxonomy Eremitis aemula F.M. Ferreira & R.P. Oliveira sp.nov.(Fig. 1) Etymology: The specific epithet "aemula", from the Latin, means "what imitates, who seeks to match" (Faria 1956), a reference to the morphological complexity of the new species, overlapping other congeneric species in various morphological characters.
Type   (Soderstrom et al. 1988;Clark 1990;Judziewicz et al. 1999).The Baixo Jequitinhonha region includes areas considered to be of extreme biological importance to the conservation of the Minas Gerais flora (Drummond et al. 2005).
Conservation status: The new species is only known from one small population occurring in the Alto Cariri State Park, in northeastern Minas Gerais.Júlio A. Lombardi cited, on the herbarium label (Lombardi et al. 5992), the locality as Duas Barras Farm, near to the Minas Gerais/Bahia border (see paratype section below).However, at that time, the Alto Cariri State Park had not been created yet.Therefore, both collections were made at the same locality, and there is a single population of E. aemula known so far.
This species is microendemic to this region.About 50 individuals were observed in the field.According to the IUCN Standards and Petitions Committee (2019), criteria B2ab(ii, iii), Eremitis aemula should be considered Critically Endangered (CR).We suggest this category because the species has a very restricted geographic distribution and area of occupancy (AOO = 4 km 2 ).Although the species occurs in a Conservation Unit, throughout the Baixo Jequitinhonha region, there is significant conversion of native vegetation for areas of pasture, agriculture, and mining activities (Mascarenhas et al. 1989;Ribeiro & Galizoni 2003), which puts the preservation of this species at risk.

Table 1 .
Morphological and geographical distribution comparisons among the new species Eremitis aemula with E. jardimii and E. robusta.