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Research Article
A new species of Epidendrum L. (Orchidaceae) of pendulous habit from Peru
expand article infoLuis Ocupa Horna§|, Eric Hágsater, Marco M. Jiménez|#
‡ Centro de Investigación en Biología Tropical y Conservación, Piura, Peru
§ Instituto de Ciencias Antonio Brack, Lima, Peru
| Grupo Científico Calaway Dodson: Investigación y Conservación de Orquídeas del Ecuador, Quito, Ecuador
¶ Herbario AMO, Mexico City, Mexico
# Vivero de Conservación La Paphinia, Zamora Chinchipe, Ecuador
Open Access

Abstract

A new species of Epidendrum L. from northern Peru is described, illustrated, and compared with related species. This new species belongs to the Laxicaule Group and shares morphological characteristics with Epidendrum laxicaule D.E. Benn & Christenson but differs in the shape and length of the dorsal sepal; the shape of the petals and the lip, ribs position of the lip, shape of the vesicle formed between the ovary and the column as well as the section of the stem.

Abstract

Se describe, ilustra y compara una nueva especie de Epidendrum L. del norte de Perú con otras especies relacionadas. Esta nueva especie pertenece al Grupo Laxicaule y comparte características morfológicas con Epidendrum laxicaule D.E. Benn & Christenson pero difiere en la forma y longitud del sépalo dorsal; la forma de los pétalos y del labio, la posición de las costillas del labio, la forma de la vesícula formada entre el ovario y la columna así como la sección del tallo.

Keywords

Cajamarca, endemic, Epidendroideae, epiphyte, neotropic, San Ignacio

Introduction

The genus Epidendrum Linnaeus (1763: 1347) are terrestrial, epiphytic and lithophytic plants that occur in different types of vegetation ranging from tropical forests, coastal dunes and scrubs to Andean paramos (Hágsater and Soto 2005; Chase et al. 2015). The genus ranks as one of the most diverse among Neotropical orchids, with around 2400 species (Hágsater et al. 2016), 1500 of them being recently treated and illustrated in the Icones Orchidacearum series (Hágsater and Salazar 1993; Hágsater et al. 1999; Hágsater and Sánchez 2001, 2004, 2006, 2007, 2008, 2009, 2010, 2013, 2015a, 2015b; Hágsater and Santiago 2018a, 2018b, 2019, 2020a, 2020b, 2021).

Though there have been many attempts to separate Epidendrum into various genera (Hágsater 1985; Hágsater and Soto 2005), it has been argued that it is best left as a single large genus reflecting its monophyly, as revealed by molecular studies (Hágsater and Soto 2005; Hágsater et al. 2019; Granados et al. 2020). Groups of species within Epidendrum can be cohesively aggregated based on vegetative and floral characteristics, which are also supported by molecular information. As this work is in progress, no formal sub-generic classification has been proposed to date, based on the informal groups recognized in current taxonomic practice (Hágsater 1985; Hágsater and Huayta 2018).

This is the case of the Laxicaule group, endemic to Peru, which is characterized by the pendulous, monopodial habit, with sub-apical branching, the laterally compressed to ancipitous stems, the relatively short leaves, the short racemose, few-flowered inflorescences, the large flowers and the lip with prominent ribs (Hágsater and Huayta 2018). Presently, there are only two species in the group: Epidendrum laxicaule D.E. Benn & Christenson and E. megalopentadactylum Hágsater & Huayta (Hágsater and Huayta 2018) found in central Peru. Here we are describing, illustrating and representing with photographs a new species of Epidendrum, E. lufinorum Ocupa & Hágsater, as well as photographs of the related species and two undescribed species. A table is provided with the characteristics that distinguish the three species of the Laxicaule Group for which information is available.

Material and methods

A living plant in flower of the new species was collected in March 2016 during a botanical expedition to Cerro Parcos in the department of Cajamarca, northeastern Peru. The photographs were taken in situ using a Canon Rebel T3 camera equipped with a Canon EF-S 18–55mm f/3.5–5.6 lens and were later used for preparing the line drawing and figures. Fresh flowers were preserved in 70% ethanol and 1% glycerol. The single collected plant was dried to make a herbarium specimen, which was afterwards deposited in the Herbarium Truxillense (HUT, acronym following Thiers 2021, updated continuously), Trujillo, Peru.

In order to determine the taxonomic status of the collected specimen, we examined all relevant Epidendrum material from USM and MOL (acronym following Thiers 2021, updated continuously), because both herbaria have a large collection of Epidendrum species. The original descriptions from holotypes of related species (Bennett and Christenson 1998; Hágsater and Santiago 2018a) were consulted and compared. Additionally, some online resources including the scans of relevant type specimens were accessed such as the JSTOR Global Plants web portal (https://plants.jstor.org). A distribution map of the proposed new species and related species, was prepared using the software QGIS 3.10 (QGIS Development Team 2020). The holotype specimen was collected under the research permit for the project “Estudios Taxonómicos Selectos de la Flora del Norte del Perú” with Resolution N° 247 –2016 –SERFOR/DGGSPFFS and the extension Resol. 430–2017.

Taxonomic treatment

Epidendrum lufinorum Ocupa & Hágsater, sp. nov.

Figs 1, 2, 4C

Type

Peru. Cajamarca: San Ignacio, in a coffee plantation, close to the caserío Villa Rica, DDM 5°5.1607'S, 78°53.2076'W, elev. 1690 m, 03 April 2016, Ocupa 211 (holotype: HUT!).

Similar to Epidendrum laxicaule D.E.Benn & Christenson, but differs in having smaller dorsal sepal (i.e. 2.4 × 0.4 cm vs. 3.2 × 0.6 cm) which is oblong-oblanceolate (vs. narrowly oblanceolate), with an obtuse apex (vs. acute), the linear and obtuse petals (vs. narrowly linear-lanceolate and acuminate), lip transversely cordate (vs. transverse), disc with 5 parallel and central ribs (vs. 5 parallel ribs projecting distally), a gibbous vesicle (vs. globose) and the stem section terete (vs. elliptic).

Figure 1. 

Drawing of Epidendrum lufinorum sp. nov. A habit B flower C dissected perianth D lip extended E column, lip and ovary, lateral view F lip in natural position, abaxial view G anther and pollinarium. Illustration by L. Ocupa from the holotype (L. Ocupa 211, HUT).

Description

Epiphytic herb, monopodial, branching, pendulous, slender, about 72 cm long including inflorescence. Roots 2 mm in diameter, basal, white, fleshy. Stems ca. 65 cm long, terete in cross section, new shoots produced from sub-apical nodes of primary stem, enveloped by tubular, fleshy, articulated, green with vinaceous spotted sheaths, membranaceous near leaf abscission, articulate and leaf-bearing above. Leaves 5.5–7.2 × 0.38–0.4 cm, linear, sessile, distichous, fleshy, semi-terete, descending, facing downwards, sulcate below, apex obtuse; sheaths 2.5–5.0 cm long, tubular, appressed, green with vinaceous spots as well as leaves. Inflorescence 7 cm long, apical, pendulous, 1–2-flowered, covered to mid portion by 3 successive, imbricating sheaths; peduncle ca. 4.4 cm long, terete, green with pale vinaceous spots; rachis 2 cm long, terete; sheaths 0.8–2.2 × 0.2–0.3 cm, green with vinaceous spots, ensiform, tubular, laterally compressed, ancipitous, apex acute, decreasing in size. Floral bracts 2.5 × 1.5 mm, fawn-colored with vinaceous spots, longitudinally triangular, minute, apex acuminate, base truncate. Ovary ca. 2 cm long, pedicellate, green with vinaceous spots, progressively thickened towards apex, slightly recurved, with 3 longitudinal furrows, one adaxially and two laterally, forming a ventral gibbose vesicle at the apex with basal portion of column. Flowers 1–2, lax, pendulous, resupinate, unscented; sepals and petals green, dorsally tinged reddish brown, abaxially with vinaceous spots and white margin; lip cream, becoming amber as it ages; column light green with vinaceous dorsal side. Dorsal sepal 2.4 × 0.4 cm, free, oblong-oblanceolate, arched forward, 5–veined, slightly concave in middle portion towards apex, 3–canaliculate abaxially, margins attenuate, apex obtuse. Lateral sepals 2.3 × 0.75 cm, free, obliquely oblong-oblanceolate, arched forward, 5-veined, slightly convex at base towards middle portion, margin slightly revolute, involute in middle portion towards apex, apex acute, dorsally keeled. Petals 2.2 × 0.2 cm, free, linear, slightly incurved, slender, 1–veined, longitudinally somewhat oblique, obtuse, margins slightly recurved. Lip 2.2 × 2.0 cm, 3–lobed, transversely cordate, apex emarginate, fleshy, rigid, strongly revolute in natural position, margin entire; lateral lobes 11.9 × 7.2 mm, semiorbicular when expanded; mid-lobe 15 × 7.5 mm, bilobate, ecallose, disc with 5 central, parallel, prominent, fleshy and thickened ribs, fused at base, disappearing in the middle of mid-lobe, the two most lateral ribs are much less prominent. Column 13 × 4 mm, clavate, forming a prominent, ventral, gibbose vesicle at base with apical portion of ovary; clinandrium-hood much reduced, margin entire. Anther 2.5 × 2.1 mm, broadly elliptical, yellowish green. Pollinia 4, fulvous, in 2 nearly equal pairs, obovoid, flattened at interfaces, caudicles attaching them in pairs, granulose, viscarium semi-liquid, translucent. Capsules not seen.

Figure 2. 

Epidendrum lufinorum sp. nov., photographed in situ at the type locality A habit with stem apex including inflorescence B close-up of a stem segment with a new growth in early stage C lateral view of flower D abaxial view of flower with ovary and apical vesicle. Photographs by L. Ocupa (based on the holotype: L. Ocupa 211).

Eponymy

The epithet is an acronym formed by the first two letters of the names Luis (1966–), Fiorella (1993–) and Noemí (1970–), parents and sister of the first author, to whom he wishes to dedicate this species.

Distribution, habitat and comments on the conservation of the species

This species is currently known only from the type locality in the northern zone of Peru, near the base of the hill known locally as Cerro Parcos, in the village of Villa Rica, San José de Lourdes district (Fig. 3). The habitat of Epidendrum lufinorum is within an area with high agricultural activity such as the cultivation of Coffea arabica L. (Rubiaceae Juss.). No more individuals of this species were found in the surrounding areas, but a fertile individual (holotype) and some other small specimens growing as epiphytes on the trunks of C. arabica plants, occasionally sharing the same phorophyte with other orchid species such as Gongora aromatica Rchb.f., Masdevallia glandulosa Königer, Stenia calceolaris (Garay) Dodson & D.E.Benn. and Telipogon astroglossus Rchb.f., which would support the hypothesis of a possible adaptation of this species to anthropized environments. However, its habitat continues to be fragmented as a consequence of tree felling, the expansion of agricultural crops and practices such as pruning and clearing coffee trees of epiphytic plants. The latter is a very common practice among the local population, as a way to maintain optimal conditions for the efficient production of coffee beans, however, it threatens the presence of the few individuals of E. lufinorum that may be growing.

Figure 3. 

Species distribution map of the Laxicaule Group. Regions: 1 Cajamarca 2 Amazonas 3 Pasco 4 Junin Prepared by Luis Ocupa.

Most of the coffee crops were located near secondary forest patches with some individuals of trees as Cedrela odorata L., Delostoma integrifolium D.Don, Erythrina edulis Triana ex Micheli and Vochysia vismiifolia Spruce ex Warm.

Phenology

Epidendrum lufinorum was observed flowering in April, at the end of the rainy season in that region.

Notes on Laxicaule Group

The combination of a monopodial pendulous habit, linear leaves, an apical inflorescence with few flowers, and a lip with a prominent ribbed disc places the new species in the informal Laxicaule Group.

There are two species in the group, both presently known from Peru: Epidendrum laxicaule and E. megalopentadactylum (Hágsater and Huayta 2018) reported in Junin and Pasco, respectively (Fig. 4A, B).

Figure 4. 

Comparison and flowers close-up of the Laxicaule Group species A E. laxicaule (Photo by I. Rolando) B E. megalopentadactylum (Photo by F. Corcuera) C E. lufinorum sp. nov. (Photo by L. Ocupa).

Among the two species belonging to the Laxicaule group, Epidendrum lufinorum is most similar to E. laxicaule, from which it differs in the shape and length of the dorsal sepal; the shape of the petals and the lip, disc ribs position of the lip; shape of the vesicle formed between the ovary and the column as well as the section of the stem. E. lufinorum is easily distinguished from the other species of the Laxicaule group by the characteristics indicated in the Table 1. It is worth mentioning that the type specimen of E. lufinorum we collected is a plant consisting of a flowering primary stem, with a new secondary branch clearly visible in its early stage of development (Fig. 2B).

Table 1.

Features distinguishing the species of Laxicaule Group.

Character E. laxicaule E. megalopentadactylum E. lufinorum
Stem section Elliptic Ancipitose Terete
Leaf size 8.5 × 0.45–0.47 cm 4.5–7.5 × 1.5–2.5 cm 5–7.2 × 0.38–0.4 cm
Inflorescence 6 cm long Sessile, compact 7 cm long
Leaf shape Linear Narrowly lanceolate Linear
Cross section leaf Semiterete Flat, conduplicate at base Semiterete
Ovary length 1.3–1.5 cm 1.6 cm 2.0 cm
Ovary vesicle Globose Absent Gibbose
Number of flowers 3–4 3–5 1–2
Dorsal sepal size 3.2 × 0.6 cm 3.8 × 1.0 cm 2.4 × 0.4 cm
Dorsal sepal shape Narrowly oblanceolate Narrowly elliptic-ovate Oblong-oblanceolate
Dorsal sepal apex Acute Acute Obtuse
Lateral sepal size 2.6 × 0.9 cm 4.0 × 1.2 cm 2.3 × 0.75 cm
Lateral sepal shape Obliquely oblong-oblanceolate Narrowly elliptic-ovate, slightly oblique Obliquely oblong-oblanceolate
Petals size 2.8 × 0.2 cm 3.8 × 1.0 cm 2.2 × 0.2 cm
Petals shape Narrowly linear-lanceolate Narrowly elliptic Linear
Petals ápex Acuminate Acute Obtuse
Lip size 2.0 × 2.6 cm 3.3 × 3.1 cm 2.2 × 2.0 cm
Lip shape and lobes Transverse, 3-lobed Suborbicular, entire Transversely cordate, 3-lobed
Disc of lip 5-parallel ribs projecting distally 5-ribs 5-parallel and central ribs
Column size 1.25 cm long 1.0 cm long 1.3 cm long
Column shape Clavate Straight Clavate

In May 2015, a specimen of another species, Epidendrum aff. laxicaule sp. nov., was found growing as an epiphyte in a montane forest in the western part of Amazonas department in northern Peru, in the Cajaruro district of Utcubamba province, at an elevation of 1685 m. It was observed and validated with photographs (Fig. 5A, B, C) by Luis Pillaca and shows vegetative and morphological characteristics similar to those of E. laxicaule and E. lufinorum. However, it has flat and thick, narrow leaves, a much more prominent vesicle at the apex of the ovary and the narrower lip with three parallel and central ribs. Pillaca indicates that the area where the specimen was found has been destroyed due to agricultural encroachment.

Figure 5. 

Other undescribed species of the Laxicaule Group found in Amazonas A, B, C Epidendrum aff. laxicaule sp. nov. and E. lufinorum D, E Epidendrum aff. megalopentadactylum sp. nov. Photographs by L. Pillaca (A, B, C) and L. Ocupa (D, E).

A year later, in the same department, but in the province of Bagua, district of Aramango, a specimen of an additional species, Epidendrum aff. megalopentadactylum sp. nov., was found as part of the private collection of Ricardo Saens Saavedra†. This specimen observed and photographed (Fig. 5 D, E) by Luis Ocupa, presents morphological characteristics similar to E. megalopentadactylum, such as pendulous plants with flat leaves, conduplicate at the base, strongly laterally compressed and ancipitous stems and an entire lip, but is distinguished by the presence of a vesicle and the lip without ribs.

Acknowledgements

The first author is grateful to Edwal Rimarachin and his family for access to his orchid collection and support during the expedition, to Ivan Tamayo-Cen for making available the description of Epidendrum laxicaule, and to Carlos Martel and Irwing S. Saldaña for their corrections and suggestions for this manuscript. The authors thank Felix Corcuera for the photograph of E. megalopentadactylum and Luis Pillaca for the photographs of another specimen of E. sp1. from Amazonas. We are grateful to the late Isaias Rolando (1956–2008) for the photograph of E. laxicaule shared with Hágsater. Finally, we are grateful to the editor and the two anonymous reviewers for their suggestions regarding the manuscript.

References

  • Bennett DE, Christenson EA (1998) New species of Peruvian Orchidaceae V. Lindleyana 13: 42–45.
  • Chase MW, Cameron KM, Freudenstein JV, Pridgeon AM, Salazar GA, van den Berg C, Schuiteman A (2015) An updated classification of Orchidaceae. Botanical Journal of the Linnean Society 177(2): 151–174. https://doi.org/10.1111/boj.12234
  • Granados Mendoza C, Jost M, Hágsater E, Magallón S, van den Berg C, Moriarty Lemmon E, Lemmon AR, Salazar GA, Wanke S (2020) Target Nuclear and Off-Target Plastid Hybrid Enrichment Data Inform a Range of Evolutionary Depths in the Orchid Genus Epidendrum. Frontiers in Plant Science 10: e1761. https://doi.org/10.3389/fpls.2019.01761
  • Hágsater E (1985) Towards an understanding of the genus Epidendrum. In Proceedings of the Eleventh World Orchid Conference. American Orchid Society, Miami, Florida, 195–201.
  • Hágsater E, Soto MA (2005) Epidendrum. In: Pridgeon AM, Cribb PJ, Chase MW, Rasmussen FN (Eds) Genera Orchidacearum 4: Epidendroideae, part one. Oxford University Press, Cambridge, 236–251.
  • Hágsater E, Sánchez L, García-Cruz J (1999) The genus Epidendrum, part 2, A second century of new species in Epidendrum, Icones Orchidacearum 3: 301–400.
  • Hágsater E, Santiago E, Martínez Rodríguez L (2016) Epidendrum lasiostachyum (Orchidaceae): A new Colombian species of the Epidendrum macrostachyum group. Lankesteriana 16(1): 27–37. https://doi.org/10.15517/lank.v16i1.23621
  • Hágsater E, Granados Mendoza C, Salazar GA, Quiroga-González S, Magallón S, van den Berg C, Moriarty Lemmon E, Lemmon AR (2019) Phylogenomics of Epidendrum: untangling a Neotropical mega-diversification. In: Pridgeon A, Arosemena AR (Eds) Proceedings, 22 World Orchid Conference, Conference Papers/Systematics. Asociación Ecuatoriana de Orquideología, Guayaquil, Ecuador, 249–254.
  • Linnaeus C (1763) Species Plantarum (2nd edn) (p. 1347). Impenis direct, London. Laurentii Salvii.
  • QGIS Development Team (2020) QGIS Geographic Information System. Open Source Geospatial Foundation. http://qgis.org [accessed 10.06.2021]
  • Thiers B (2021) Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden Virtual Herbarium, The Bronx. http://sweetgum.nybg.org/ih/ [accessed 10.06.2021]

Supplementary material

Supplementary material 1 
Luis Ocupa Horna, Eric Hágsater, Marco M. Jiménez

Data type: species data

Explanation note: Epidendrum lufinorum, found in northern Peru, it similar with Epidendrum laxicaule D.E.Benn & Christenson but differs in the shape and length of the dorsal sepal; the shape of the petals and the lip, ribs position of the lip, shape of the vesicle formed between the ovary and the column as well as the section of the stem.

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
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