Materials and methods

Botanical material. The material studied was collected in an area located in the District of Sicchez, Province of Ayabaca, department of Piura, under permit RD N° D000148-2022-MIDAGRI-SERFOR-DGGSPFFS-DGSPF, granted by the Servicio Nacional Forestal y de Fauna Silvestre (SERFOR), and as a result of the project “Orquídeas en el Distrito de Sicchez, Ayabaca-Piura” overseen by one of the authors (KAP). Morphological and ecological data of the specimens were recorded in situ. The collected specimen was prepared for the herbarium (^{Hágsater 1978}) and deposited at USM (acronyms according to ^{Thiers 2023}, continuously updated). Additionally, the flowers were preserved in a solution of 5 % glycerin, 25 % distilled water and 70 % alcohol (^{Calatayud 2005}) for the subsequent study of floral structures.

Description and additional information. The collected material was compared with the descriptions and drawings of Encyclia species documented in ^{Dodson (1977}, ²⁰⁰¹⁾, ^{Dodson & Dodson (1980)}, and ^{Dodson & Luer (2010)}. Likewise, Encyclia vouchers available online (AMES, GH, K, MO, and SEL) and those deposited in the USM, HOXA, HUT and CPUN herbaria were consulted. Based on the collected material and the protologue of E. naranjapatensis, the occurrence of this species in Peru is confirmed and an updated description of the species is presented (modified from ^{Dodson 1977}). Taxonomic comments on the species and its phylogenetic relationships are also included. Additionally, photographs, information on geographic distribution, and ecology are presented. Furthermore, a map of occurrences for E. narajapatensis in Ecuador and Peru is provided, using ArcGIS pro software v. 3.0.3 . The botanical terminology followed ^{Beentje (2016)} and ^{Stearn (2004)}.

Conservation status. The conservation status of Encyclia naranjapatensis was assessed using the IUCN Red List criteria (^{IUCN 2022}). Since data for the species were generally only available from herbarium vouchers and published reports in articles and books, we relied primarily on B criteria, geographic distribution assessed as either B1 (extent of occurrence) or B2 (area of occupancy), both implemented in GeoCAT v. 3.1 (^{Bachman et al. 2011}).

Results

Encyclia naranjapatensis Dodson, Selbyana 2(1): 50. 1977. Type. Ecuador. Bolivar: Naranjapata, km 107 on railroad from Duran to Riobamba, alt. 700 m, 10 April 1961, C.H. Dodson 397 (Holotype: SEL) (Figures 1-2).

Figure 1 Illustrations of Encyclia naranjapatensis Dodson. A. Drawing by Lisa Megahee, from ^{Dodson CH. 1977}. B. Drawing by Calaway Dodson, from ^{Dodson CH & Dodson PM, 1980}: pl. 69. Courtesy, Marie Selby Botanical Gardens.  

Figure 2 Composite plate of Encyclia naranjapatensis Dodson. A. Habit. B. Flower. C. Dissected perianth. D. Lip, column, and ovary, lateral view. E. Column, ventral and three quarters-views. F. Anther cap and pollinarium. Prepared by L. Ocupa-Horna. 

Epiphytic plant, up to 70 cm tall. Pseudobulbs ovoid-cylindrical, apically 2- or 3-foliate, 4.5-10.5 cm long, 4-6.5 cm in diameter, smooth when well hydrated or have recently developed, rough with time or dehydration. Leaves conduplicate, coriaceous, oblong-linear, obtuse, proximally three-jointed, slightly falcate, 30-60 × 1.1-3.6 cm. Inflorescence apical, starting from the mature pseudobulb, suberect to somewhat arching, paniculate, up to 90 cm long, with up to 30 flowers; peduncle cylindrical, up to 50 cm long, with 4 internodes; rachis cylindrical, up to 40 cm long; floral bract triangular, acute, 2.8-3 × 3.8-4 mm. Ovary pedicellate, green, paler on the pedicel, straight to sigmoid or arched, cylindrical, distally dilated, slightly verruculose, more noticeable distally, 2.5-2.8 cm long. Flowers with green sepals and petals, reddish-brown starting approximately 1/4 distal without covering the edge of the segment, leaving a clear green edge, the sepals with a dark spot at the apex that merges with the reddish-brown, white lip with red nerves at the base of the lateral lobes and the central lobe (approx. 8, the central one most prominent), greenish from base to middle of callus, column pale green, becoming white at the apex, yellow anther. Sepals arched forward, oblanceolate, acute, revolute, minimally mucronate, 17-20 × 5.5-6.0 mm, 7-veined; lateral sepals slightly oblique, concave. Petals arched forwards, slightly concave, spatulate-obovate, sub-acute, revolute, 17-20 × 7-10 mm, 6-veined. Lip slightly adnate at base with the column, deeply trilobed, 18-20 × 18-20 mm expanded; lateral lobes embracing the column in natural position, recurved, oblong, obtuse, basally oblique, 9-11 × 3.5-4 mm, 5-6 veined; mid lobe slightly concave, sub-quadrangular, undulate, emarginate, 11-12 × 10-11.5 mm; callus sub- rhombic, elevated, formed by two keels, broadly parallel, basally close, forming a groove which becomes an oval depression in the central part, subsequently emerges a central elevated keel, so the callus ends trifid (in 1/3 of the central lobe), 6-6.5 × 3.5 mm long. Column claviform, forming an angle of almost 120° with the ovary, dorsoventrally compressed, broadened towards the apex, somewhat curved upward at the midpoint, 10-11 mm long, the base with concave margins in dorsal view, ventral view canaliculated at the base, where the cuniculus is formed, clinandrium superficially tridentate with larger lateral teeth, with a pair of subquadrate unciform stelidia. Anther cordate, pollinia 4, in two pairs, each pollinia ca. 9 mm long, obovoid, strongly compressed laterally, bright yellow, with granular caudicles about the same length as the pollinia. Capsule dark brown, with white warts, fusiform, trilocular.

Taxonomic notes. According to ^{Dodson (1977)}, Encyclia naranjapatensis is morphologically similar to Encyclia osmantha (Barb. Rodr.) Schltr. but this last differs by deltoid (vs. sub-quadrangular), slightly emarginate (vs. strongly emarginate), and flat (vs. slightly concave) lip. However, in phylogenetic analyses, E. naranjapatensis is retrieved as sister to E. elegantula Dressler, an entity which we consider has a wide distribution from South America (Colombia; Tamayo-Cen, com. pers.), Central America, and the southeast of Megaméxico. In addition, both are nested in a clade consisting mainly of northern South American species such as E. diurna (Jacq.) Schltr., E. garciae-esquivelii Carnevali & I.Ramírez and E. profusa (Rolfe) Dressler & G.E.Pollard (^{Carnevali et al. 2022}, ^{Tamayo-Cen 2022}). Among the species belonging to this clade, E. narajapatensis shows greater morphological similarity to Encyclia diurna but it differs by its mostly green petals and sepals, sometimes with light shades of brown (vs. distinctly brown petals and sepals), the central lobe of the lip orbicular and ends with a clear apiculus (vs. sub-quadrangular and without apiculus), and distributed only in northern Venezuela (Carnevali pers. comm.) (vs. distributed in the Pacific slope of Ecuador and Peru).

For example, among Peruvian Encyclia species, E. naranjapetensis is recognized by its short rhizome, minimally verruculose ovary, yellow anther, and white lip. The other Encyclia species reported for Peru (^{Tamayo-Cen et al. 2020}) are very different vegetative and florally. For example, E. pilosa has a yellow lip (vs. white); E. microtos and E. rhizomatosa have conspicuously warty ovaries and reddish anthers (vs. minimally verruculose ovary and yellow anthers). Other species such as E. cyperifolia are easily distinguished by non-resupinate their flowers (vs. resupinate) with purple staining on most segments (vs. without purple stains), and linear leaves (vs. oblong-linear), while E. randii can be distinguished by short, few-flowered (vs. long, abundant-flowered), racemose inflorescence (vs. paniculate), and larger flowers (vs. median flowers) with the central lobe of the lip flat (vs. slightly concave), orbicular (vs. sub-quadrangular), and with an extensive purplish spot (vs. without purplish spot).

On the other hand, Encyclia naranjapatensis was previously reported for Peru by ^{Valenzuela Gamarra et al. (2022)}. However, the flower shown in Figure 146 from which this report was based, corresponds to Encyclia chloroleuca (Hook.) Neumann (Figure 3), an entity distantly related to E. naranjapatensis. Encyclia chloroleuca is one of the few species of Encyclia with North and South American distribution; it is also characterized by being morphologically variable (e.g., ^{Bastos et al. 2018}). This species has been recorded from several departments of Peru (e.g., San Martín, Loreto, Huánuco, and Pasco) and is easily differentiated from E. naranjapatensis by its plants up to 35 cm tall (vs. 75 cm tall), oblong-lanceolate sepals, 12-15 mm long (vs. narrowly obovate, 18 mm long), oblong-oblanceolate petals, 11-14 mm long (vs. spatulate-obovate, 18-20 mm long), and the central lobe of the lip "ovate to sub-orbicular, with a conspicuous apiculum (vs. sub-quadrangular, emarginate, not apiculate) (Figure 3). The picture shown by ^{Valenzuela Gamarra et al. (2022)} corresponds to a dull maroon form of E. chloroleuca (^{Tamayo-Cen et al. 2020}). The polymorphic colors in flowers of the same species can be driven by the presence of anthocyanin and carotenoid pigments in the flowers (^{Narbona et al. 2014}).

Figure 3 Composite plate of Encyclia chloroleuca (Hook.) Neumann. A. Habit. B. Flower. C. Dissected perianth. D. Lip, column, and ovary, three quarters view. E. Column, dorsal, ventral and laterals views. F. Anther cap and pollinarium. Prepared by L. Ocupa-Horna. 

Distribution and habitat. Encyclia naranjapatensis was described from a specimen collected in the locality of Naranjapata, between Riobamba and Durán, Province of Bolívar, Ecuador, growing as an epiphyte in dry valleys in rain shadow at elevations of 700 to 1000 m (^{Dodson 1977}). It was subsequently found in other localities such as the Cañar River Valley (Cañar Province), in an area near Zaruma (^{Dodson & Dodson 1980}), and in the forests around Piñas (both in El Oro Province), where it was last found in 1986 (^{Endara et al. 2017}) (Figure 4). In Peru, Encyclia naranjapatensis has been found in Ayabaca province, Department of Piura, growing as an epiphyte in a remnant of secondary forest located within agricultural areas (^{MINAM 2019}). These areas of transitory or permanent crops, together with the rest of the disturbed areas, cover 9.6 % of the surface of the Peruvian territory, and are present in many departments, such as Piura (Figure 4).

Figure 4 Occurrence map of Encyclia naranjapatensis Dodson. Prepared by A. Chorres-Arica. 

Conservation status. Encyclia naranjapatensis, previously known to be endemic to Ecuador, was classified as endangered (EN, B1) because grew in a very restricted area, where agriculture predominates (^{Endara et al. 2017}). Subsequently, it was classified as Vulnerable (VU) (^{Fernández-Fernández et al. 2018}), based on records from two localities in El Oro Province, available online.

In Peru, only a few individuals of E. naranjapatensis have been found growing on branches of trees that were felled, so its population local is probably very small and dispersed. Here, the habitat is severely threatened by fragmentation due to agricultural and cattle ranching developments, extraction of valuable timber species, and unregulated housing construction (Agurto-Palomino, pers. comm.). However, in the Sicchez orchidarium, there are specimens in cultivation (Figure 5), collected from the surrounding area, and they could be reproduced to ensure the ex situ survival of the species and conservation of germplasm native from Peru.

Figure 5 Encyclia naranjapatensis Dodson cultivated in the orchidarium of Sicchez, in Peru. A. Cluster of flowers. B. Close up of the pseudobulbs. C. Habit. Photos by A. Chorres-Arica (A) and K. Agurto-Palomino (B-C). 

Currently, the information available online on the localities of Encyclia naranjapatensis in the wild (Figure 4). Using the GeoCAT tool and IUCN methodology (^{Bachman et al. 2011}), this species is classified as EN (Endangered), as it meets IUCN criteria B1a (i, iii, iv) (2022), and has an extent of occurrence (EOO) of 3,625.709 km² and an area of occurrence (AOO) of 20.000 km² (with a cell size of 2 km). With this new report for Peru, the extension of the natural distribution of Encyclia naranjapatensis also implies an increase in habitats and populations of the species.

Although an evaluation of the categorization of the species was made in the present work, the results do not evidence any significant change in its categorization status from that previously proposed by ^{Endara et al. (2017)}.

Phenology. Encyclia naranjapatensis flowers between July and August.

Specimens examined. PERU. Piura: Prov. de Ayabaca, Distrito de Sicchez, en un bosque secundario a 1.2 km al sur de Sicchez, 4° 34' 51.25" S 79° 45' 54.68" W, 1515 m, 15 September 2022, K. Agurto P. & A. Chorres A. 001 (USM).

Additional specimens examined. ECUADOR: El Oro: Piñas, 2125 m., 04 May 1981, C. Dodson 8424A (SEL) (Figure 6). [unknown location], collected by Steve Pruyn & Richard Emery, 1991, Ex Hort. C. L. Withner 34 (GH).

Figure 6 Paratype of Encyclia naranjapatensis Dodson (SEL 030412). Courtesy, Marie Selby Botanical Gardens. 

Discussion

With the report of Encyclia naranjapatensis, there are now nine species of the genus recognized in Peru. Encyclia naranjapatensis was previously considered restricted to Ecuador, in the provinces of Bolivar and El Oro, and was categorized as an Endangered species. However, the evaluation of the Extent of Occurrence (EOO) and Area of Occupancy (AOO) for E. narajapatensis in both countries reveals that E. naranjapatensis should continue to be considered endangered, according to IUCN criteria.

This report broadens our distributional knowledge about Encyclia naranjapatensis, a rare-scare species in nature. Also, this entity is linked to Seasonally Dry Tropical Forests, a fragile and extensive ecosystem in the Neotropics. The phylogenetic reconstructions can be a tool for decision-making in conservation aspects (^{Eguiarte et al. 1999}); E. naranjapatensis and E. elegantula are basal grades in a particular clade of Encyclia, so the conservation of E. naranjapatensis would be considered by their evolutionary information. In addition, these data are essential for ongoing work on the genus as a model for predicting how have been species distributed in space-time.