Research Article |
Corresponding author: Luis Ocupa Horna ( luisocupa.horna@gmail.com ) Academic editor: Murielle Simo-Droissart
© 2021 Luis Ocupa Horna, Eric Hágsater, Marco M. Jiménez.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Horna LO, Hágsater E, Jiménez MM (2021) A new species of Epidendrum L. (Orchidaceae) of pendulous habit from Peru. PhytoKeys 184: 55-66. https://doi.org/10.3897/phytokeys.184.70844
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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.
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.
Cajamarca, endemic, Epidendroideae, epiphyte, neotropic, San Ignacio
The genus Epidendrum
Though there have been many attempts to separate Epidendrum into various genera (
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 (
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
In order to determine the taxonomic status of the collected specimen, we examined all relevant Epidendrum material from USM and MOL (acronym following
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).
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.
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).
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.
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.
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.
Epidendrum lufinorum was observed flowering in April, at the end of the rainy season in that region.
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 (
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
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.
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.
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.
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.