﻿Pitcairniaabscondita (Pitcairnioideae, Bromeliaceae), a hidden novelty from north-western Jalisco, Mexico

﻿Abstract Pitcairniaabsconditasp. nov., known until now only from the Municipalities of Cabo Corrientes, Mascota, Puerto Vallarta, San Sebastián del Oeste and Talpa de Allende in the State of Jalisco, Mexico, is here described and illustrated. The new taxon was confused with P.imbricata for long time, but differs from this species by its green floral bracts with the apex divergent to spreading (vs. red and appressed) and by the appendiculate at the base chartreuse-green petals (vs. not appendiculate yellow petals). Images and a distribution map of the taxa are presented.


Introduction
Pitcairnia L'Hér. (L'Héritier 1789(L'Héritier -1790(L'Héritier [1788) with ca. 409 spp. (Gouda et al. 2021, continuously updated) is the second richest genus in Bromeliaceae and is mainly distributed in South America, but has an important centre of diversification in Mexico. The only species of the family that grows out of America, P. feliciana (A. Chev.) Harms & Mildbraed (Harms and Mildbraed 1938), belongs to this genus. Out of the 19 genera of Bromeliaceae present in Mexico (Espejo-Serna et al. 2004;Espejo-Serna 2012;Espejo-Serna and López-Ferrari 2018, here updated), Pitcairnia occupies the third place in number of taxa, with 54 species (including the one described here). In addition, the genus is notable for the number of endemic taxa present in the country, which reaches 47 species (87.03% of the total). For Jalisco, we have so far reported 13 species (Espejo-Serna et al. 2004;Espejo-Serna and López-Ferrari 2018, here updated) and, with this new find, that number increases to 14. Of these, P. singularis Flores-Arg., Espejo & López-Ferr., (Flores-Argüelles et al. 2017), P. lokischmidtiae Rauh & Barthlott (Rauh and Barthlott 1987; see also Rauh 1987) and the new taxon here proposed are restricted to Jalisco.
During the fieldwork for the fulfilment of the Master's Thesis of the first author (Flores-Argüelles 2020), we had the opportunity to collect specimens from one species of Pitcairnia, which we could not identify. Recently, reviewing specimens of the family Bromeliaceae collected in Jalisco, we found additional material of this species. After a detailed examination of the specimens, we have not been able to assign it to any of the previously-described species of the genus, so we propose it here as new to science.

Material and methods
Plants were collected in the years 2019 and 2020 in the Municipality of Cabo Corrientes, Jalisco, Mexico. The gathering of the specimens was carried out in accordance with Lot and Chiang (1986). Measurements and description were made from fresh material and herbarium specimens. The morphological terms used in the description are those proposed by Radford et al. (1974) and Scharf and Gouda (2008). The type material was deposited at Herbario Metropolitano Ramón Riba y Nava Esparza, Universidad Autónoma Metropolitana Iztapalapa (UAMIZ). We revised herbarium material of the genus Pitcairnia housed at A, C, CHAP, CICY, ENCB, FCME, GH, HEM, IBUG, IEB, MEXU, MICH, MO, P, SERO, UAMIZ, UC, US, XAL and ZEA (ac-ronyms according to Thiers 2021). To ensure the status of the proposed new species, we revised the protologues, living specimens as well as herbarium specimens and type material of P. imbricata (Brongn.) Regel (Regel 1868) and P. wendlandii Baker (Baker 1881), the taxa with morphologically most similarities (see Appendix 1). The distribution map of the species was elaborated with the open source geographic information system QGIS (2021), using the data obtained from the herbarium specimen labels. Diagnosis. Similar to Pitcairnia imbricata, but differs by the presence of green, widely oblong to widely ovate floral bracts with the apex divergent to spreading (vs. red elliptic with the apex appressed to the rachis), arcuate corollas (vs. erect), appendiculate, chartreuse-green, 9.4-9.8 cm long, petals (vs. yellow, not appendiculate 6.5-6.6 cm long).
Etymology. The specific epithet refers to the fact that, for a long time, the specimens of this species was "hidden" behind the name Pitcairnia imbricata (see McVaugh 1989), to difficulties in identifications of herbarium samples, since the dried specimens of P. abscondita can be easily confused with P. imbricata.
Distribution and habitat. Pitcairnia abscondita is known until now only from the State of Jalisco, in the Municipalities of Cabo Corrientes, Mascota, Puerto Vallarta, San Sebastián del Oeste and Talpa de Allende (Fig. 3), growing rupicolous or terrestrial in wet Pinus-Quercus forests, gallery forests and cloud forests often near rivers or streams, at an elevation interval from 400-1,500 m a.s.l. Blooms during July and fructifies from August to September.
Comments. In herbarium specimens, Pitcairnia abscondita superficially resembles P. imbricata and/or P. wendlandii. However, the new taxon differs from these two Chiapas, Guerrero, Oaxaca species by the characters shown in Table 1 and Fig. 2. In fact, the Jalisco material that McVaugh (1989) included in his Flora Novo-Galiciana as P. imbricata, actually belongs to the new species. The flowers of Pitcairnia abscondita last only one night, opening between 7.30 and 9.30 pm and remain that way during the night, starting to close at 7.30 in the morning, being completely closed at 9.00 am, so they are likely associated with a pollination syndrome by moths or bats, different from P. imbricata which, due to its red floral bracts and yellow flowers of diurnal anthesis, is associated with an ornithophilic pollination syndrome (Proctor et al. 1996).
As far as we know, the plants of P. abscondita are not used by the inhabitants of the region, so we think that the species has no immediate human pressure; however and due to the lack of detailed information about the precise distribution of the species, we suggest the inclusion of the new taxon in the Not Evaluated (NE) category of the IUCN (2020).