First record of Pogoniopsis Rchb . ( Orchidaceae : Triphorinae ) in Santa Catarina state , southern Brazil

Pogoniopsis is an endemic and myco-heterotrophic orchid genus with only two species in Brazil that can be found growing under dense canopy. Pogoniopsis schenckii is more widely distributed, with records in the states of Bahia, Minas Gerais, Paraná, Pernambuco, Rio de Janeiro, and São Paulo. Here we record P. schenckii for the first time in Santa Catarina state, southern Brazil, in a subtropical broadleaved forest, as well the genus Pogoniopsis itself, expanding its southern distribution limit. In addition, a description and a distribution map of the collected specimens are presented.

The relationships of Pogoniopsis remain unclear, because morphological studies placed Pogoniopsis in subtribe Pogoniinae (Cameron and Chase 1999;Chase et al. 2003) or Triphorinae (Cameron 2003).In a morphological and molecular study, Pansarin et al. (2008) verified that Pogoniopsis shares many morphological traits with subtribe Galeolinae, but molecular data using ITS region suggest a basal position among tribe Pogonieae.Chase et al. (2015), however, argued that taxon sampling and molecular analyses were not sufficiently robust in that study, and again placed the genus in subtribe Triphorinae, closely related to Monophyllorchis Schltr., Psilochilus Barb.Rodr.and Triphora Nutt.
Comparing the two species, P. schenckii has the largest range, with previous records from Bahia, Minas Gerais, Paraná, Pernambuco, Rio de Janeiro, and São Paulo states, while P. nidus-avis is currently recorded only from Minas Gerais and Rio de Janeiro states (Pabst and Dungs 1975;Cardoso and Queiroz 2008;BFG 2015).Currently P. schenckii is categorized as Least Concern (LC) in the Red List of the Brazilian Centre for the Conservation of the Flora following IUCN Red List criteria, due to its large distribution area, no ornamental appeal, and occurrence in conservation units of integral protection (Prieto and Messina 2012).
During recent surveys in the Parque Nacional da Serra do Itajaí, Santa Catarina state, southern Brazil (Figure 1), specimens of a terrestrial, aclorophyllous orchid were found growing on soil, under dense canopy (Figure 2A).The local vegetation is classified as subtropical lower hills broadleaved forest according to Oliveira-Filho (2015).Specimens were photographed, collected and deposited in the Herbarium FURB (abbreviation follows Thiers 2016).The species was identified as P. schenckii through illustrations provided by Hoehne (1949) and Pabst and Dungs (1975).So far, this genus was not recorded in Santa Catarina state by BFG (2015) as well as in the Orchidaceae revisions by Pabst (1951Pabst ( , 1952Pabst ( , 1953Pabst ( , 1954Pabst ( , 1956Pabst ( , 1957Pabst ( , 1959)).
The plate was edited with GIMP 2.8 and CorelDRAW X7 17.1 softwares.The distribution map was made using ArcGIS 10 software (ESRI 2010).Morphological terminology follows Font Quer (1953).

Notes oN GeoGraphic DistributioN
Taxonomic comments: The 3-lobed labellum, the finely laciniate to fimbriate margin in the middle lobe and the bigger size of the plants distinguish this species from otherwise similar P. nidus-avis.Other remarkable features are the three hairy stripes in the labellum and the small pinkish portion at basis of perianth.Also, the measures provided by Cogniaux (1893Cogniaux ( -1896) ) are slightly larger than the measurements obtained from the examined specimens.The circumscription of the two species needs to be revalued, because the illustration in Cogniaux (1893Cogniaux ( -1896) ) disagrees from the one provided by Pabst and Dungs (1975).
Preliminary microscopic analyses (Kemmelmeier pers.comm.)revealed septate fungal hyphae on the roots of the plants, not belonging to the Glomeromycota but to Ascomycota or Basidiomycota instead.However, there is no evidence that those hyphae belong to the mycobiont organism.This is the first record of the genus for Santa Catarina state, as well as the southernmost record, as the previous southernmost record was in Paraná state (Pabst and Dungs 1975).As stated above, the species can be rare and with small populations, or have just being poorly collected, due to its short period of life.The record of the species in a protected area may mitigate threats that should not be dismissed until new records of this species are found.

Figure 1 .
Figure 1.Location of the first record of Pogoniopsis in Santa Catarina state (black), southern Brazil and the current distribution of Pogoniopsis schenckii (gray).
Figure 2. Pogoniopsis schenckii.A. General view of the plants and habitat.B. Detail of the flower.C. Habit, showing the adventitious root system.D. Dissected perianth, excluding the labellum.E. Detail of the labellum.F. Detail of the ovary and column.