﻿A new species of Piper (Piperaceae) with peltate leaves from Serranía de las Quinchas, Colombia

﻿Abstract Piperquinchasense is described and illustrated as a new species occurring in the understory of wet montane forest of the middle Magdalena Valley in Colombia, the easternmost portion of the Chocó Region. Its relationships are discussed with related taxa from the Macrostachys clade. An identification key for 35 Neotropical Piper species with peltate leaves is provided.


Introduction
Piper, with more than 2000 species (Callejas-Posada 2020), is one of the most species-rich genera among flowering plants (Frodin 2004). Piper is also a common element in the understory of Neotropical forests (Gentry 1990;Draper et al. 2021). Species of Piper are a key resource for bats of the genus Carollia (Fleming 2004;Bohlender et al. 2018;Yohe et al. 2021), and they are a critical element that supports diverse trophic networks that involve moths and parasitoid wasps (Wilson et al. 2012;Slinn et al. 2018). Piper's enormous diversity of secondary metabolites is critical for their coexistence (Salazar et al. 2016a(Salazar et al. , 2016b and diversification (Massad et al. 2022). And it is also of immense interest in the pharmaceutical industry (Perez Gutierrez et al. 2013;Salehi et al. 2019). This genus is, without doubt, an essential structural and trophic element PhytoKeys 227: 9-24 (2023), DOI: 10.3897/phytokeys.227.101405 M. Alejandra Jaramillo et al.: Piper quinchaense, a new species of Piper with peltate leaves of the understory and lower strata of Neotropical forests (Salazar et al. 2016b;Draper et al. 2021).
Molecular phylogenetic studies have been instrumental in reviving the infrageneric classification of the genus, but also identifying convergence in morphological traits (Jaramillo and Callejas-Posada 2004;Trujillo et al. 2022). Molecular phylogenetics (Jaramillo and Manos 2001;Jaramillo et al. 2008) have validated the monophyly of groupings proposed in the mid-1800s (Kunth 1839;Miquel 1843). The infrageneric classification was not used during the 1900s, probably as the expeditions in the early 1900s produced too many species to classify. Today we know that Piper clades and subclades are easy to recognize with a combination of key morphological characters (Jaramillo et al. 2008). A formal infrageneric classification of Piper based on phylogeny is under preparation (Callejas pers. comm.). Molecular phylogenetics have been instrumental in clarifying the relationships of Piper species with "axillary" inflorescences, a polyphyletic set of taxa from the Chocó Region that were wrongly merged in the genus Trianaeopiper Trel. (Trelease 1928). Molecular phylogenetics demonstrated that Trianaeopiper is not monophyletic, revealing that the diagnostic character axillary inflorescence -which are shortened sympodial branches, is convergent (Jaramillo and Callejas-Posada 2004). Similarly, molecular phylogenetics have further supported that Piper species with peltate leaves are part of at least four Neotropical Piper clades (Trujillo et al. 2022). Piper classification, evolution and ecological studies have been greatly enriched with molecular phylogenetics.
Identifying Piper species continues to be difficult for the untrained eye, and many taxa are submerged in a few large, broadly distributed, but artificial taxa (Tebbs 1990(Tebbs , 1993. To the trained specialist, new Piper species are a common finding in the tropical forests, or even in the undetermined piles in the most important herbaria around the world. Additionally, molecular phylogenetics have confirmed the clade (subgeneric) affiliation of new species (Bornstein et al. 2014;Tepe et al. 2014;Trujillo et al. 2022). During our exploration to Serranía de las Quinchas we have identified a few undescribed species, one of the standsout because it has peltate leaves, a characteristic rarely observed in the genus.
"Serranía de las Quinchas" is a small mountain spur west of the Cordillera Oriental in the middle Magdalena Valley, in Colombia. The region's flora is particularly interesting as it combines its own floristic elements, mixed with taxa from Mesoamerica, the Chocó Region, and Amazonia (Balcázar-Vargas et al. 2000). Additionally, various endemic species and genera occur in the area (Rodríguez-Duque et al. 2021). The middle Magdalena Valley deserves close examination and more fieldwork to uncover the history of its biological richness. For centuries, the forest has been preserved because of its scarp ridges and high rainfall. However, the construction of a pipeline and road in the 1990s opened the area to colonization (Stiles and Bohórquez 2000). Today the region is threatened by the extension of agriculture and mining activities. Fortunately, Serranía de las Quinchas Regional Park was created in 2008 by Corpoboyacá (the regional environmental protection agency) to protect the remaining forest (Bohorquez-Osorio et al. 2020). Despite the deforestation in the region, new species are still being encountered. Here we describe a new species of Neotropical Piper with peltate leaves that we detected during our expeditions in this interesting location.

Materials and methods
Specimens were collected in Serranía de las Quinchas, located in the middle Magdalena Valley in Colombia, in the department of Boyacá. The sites visited range from 800-1200 m. a. s. l., the locality is dominated by humid montane forest (Fig. 1). Annual rainfall is 3333 mm on average; two dry seasons occur in January-February and June-August, and the average temperature is 26 °C (Instituto de Hidrología, Meteorología y Estudios Ambientales, IDEAM). Detailed observations in the field, combined with examination of available herbarium collections, allowed the description of growth habits and phenological stages. Voucher specimens were deposited in the following herbaria HUA, H-UPTC, and UMNG-H (herbarium acronyms according to Index Herbariorum [Thiers continuously updated], and Instituto Humboldt -Red Nacional de Colecciones [http:// rnc.humboldt.org.co/wp/]). In addition, taxonomic literature on Piper was examined (Trelease and Yuncker 1950, Steyermark 1984, Callejas-Posada 2020. The measurements included in the description below are based on herbarium specimens collected by the authors. Conservation status assessments employ the categories and criteria of the IUCN (2012IUCN ( , 2022. We calculated the extent of occurrence and area of occupancy using the R package ConR (Dauby et al. 2017).
For preparing the key of Neotropical Piper species with peltate leaves we used the literature (Trelease and Yuncker 1950, Steyermark 1984, Callejas-Posada 2020, Carvalho-Silva et al. 2022) and type specimens were examined using digitized plant specimens available on-line from JSTOR Global Plants (https:// plants.jstor.org/).
We extracted DNA from silica gel dried tissue, using the DNAeasy plant mini kit (Qiagen, Valencia, California, USA). The ITS region was amplified using one of two pairs of primers ITS5-ITS4, or LEU1-ITS4 (Baldwin 1992). Sequencing was contracted with GenCore (Universidad de los Andes, Bogotá, Colombia). The resulting sequences (Table 1) were manually aligned against previously obtained alignments (Jaramillo et al. 2008). We selected 43 ITS sequences from the large alignment to portray here. Three sequences from Piper species from Asia and the South Pacific were used as outgroups. Forty sequences of Neotropical Piper, comprising representatives of all clades, and 14 species with peltate leaves were selected. Maximum Likelihood (ML) phylogenetic and bootstrap (100 replicates) analyses were conducted using RAxML (Stamatakis 2014 Description. Piper quinchasense is similar to P. parianum, it differs from the latter in having all leaf blades peltate (vs. leaves deeply lobed to peltate), and inflorescence peduncle 4-5 cm long, (vs. peduncle 1-2.7 cm long).
Distribution and habitat. The species is only known from the type locality Serranía de las Quinchas (Fig. 1). Piper quinchasense is a tall shrub in the understory of very humid forests; it often grows near streams. The occurrence of stilt roots (Fig. 2C), a character not commonly seen in Piper, suggests it is adapted for flooded areas near watercourses. It also is a very resilient plant that will produce adventitious roots if tumbled and it will continue growing, or even resprout, from a fallen leaf. Resprouting is common among shade-tolerant Piper (Lasso et al. 2009).
Phenology. Flowering specimens were collected in March, and May. Fruiting specimens were collected in October.
Etymology. The epithet quinchasense, refers to Serranía de las Quinchas, the type locality for this species. According to locals, Quinchas derives from the indigenous groups "Quinchos" that inhabited the region.
Conservation status. This species is known only from one population in the type locality (Fig. 1). The extent of occurrence (EOO) of 8 km 2 and area of occupancy (AOO) of 8 km 2 are very small. The locality is under threat of disappearing for the extension of agricultural and mining activities (Rodríguez-Duque et al.

2021), which suggests it is Endangered [EN B1a
]. Serranía de las Quinchas was declared a Regional Park in 2008; since its creation, the park extension has been reduced by 20% as the buffer zones were eliminated. Furthermore, the constant threat of coal mining makes the locality highly exposed to deforestation. Notes. Piper quinchasense is a handsome species that differs from related Macrostachys taxa in having long lanceolate-oblong leaves. It is morphologically similar to P. parianum from which it differs in having mononomorphic leaves (all of them peltate) vs. leaves dimorphic, some peltate and others are deeply lobed. P. parianum is only known in the isolated cloud forests of "Peninsula de Paria", a region located in the eastern portion  A key to species of Neotropical Piper with peltate leaves is presented below.

New status
While preparing the key for peltate Neotropical Piper, we realized some species deserve new status. New status and new names are proposed for two species.  (Steyermark 1984). These species are similar in their overall morphology and potentially form a species complex. Unfortunately, we do not have sequence data to test the latter hypothesis. Here we consider them separate species. P. veraguense has glabrous leaves with nerves puberulent on the abaxial surface, not pellucid dotted (Callejas-Posada 2020); P. albert-smithii is distinct because it has fleshy warts below the nodes, and leaves are glabrous (Trelease and Yuncker 1950); and P. mutisii has fleshy warts below the nodes, nerves are dense velvety puberulent on abaxial surface; P. neovenezuelense has glabrous internodes without warty outgrowths, and nerves pilose on abaxial surface. T. Yuncker provided a key to four varieties of Piper mikanianum (Kunth) Steud: P. mikanianum (Kunth) Steud var. mikanianum; P. mikanianum f. clausum characterized by the closed sinus and overlapping lobes; P. mikanianum var. pilosius C. DC. with leaves and stems strongly pilose with hairs up to 1mm long; and P. mikanianum var. peltatum Yunck with peltate leaves and nerves minutely hirtellous on the abaxial surface (Yuncker 1972). Yuncker had mentioned that this latter variety might deserve species rank, we propose to make the change suggested and propose the new name P. andersii. Furthermore. P. mikanianum occurs in the states of Minas Gerais, Paraná and Rio Grande do Sul in Brazil and in Argentina, P. andersii, with peltate leaves has only been registered from the state of Minas Gerais. 10 Leaves up to 50cm long, sinus closed, longer lobe overlapping the petiole, peduncle 1. A.Jaram., sp. nov. on previous versions of the manuscript. We thank K. Gandhi for his expert advice on nomenclatural issues regarding the new names proposed here. Special thanks to the Galvis Family: Don Lucindo, Doña Edilsa and Leidy for hosting our field expeditions in Serranía de las Quinchas. Don Lucindo's expert guidance in the forest was key to finding the plants. This work was supported by project "BPIN No. 2020000100003 -Investigación de la biodiversidad de Boyacá: complementación y síntesis a través de gradientes altitudinales e implicaciones de su incorporación en proyectos de apropiación social de conocimiento y de efectos de cambio climático." Funds for field expeditions were also provided by Universidad Militar Nueva Granada as part of the Plant Taxonomy and Systematics course. Gencore (Sequencing Center) at Los Andes University partially subsidized the sequencing analysis.