Epidendrum lufinorum Ocupa & Hagsater, 2021

Horna, Luis Ocupa, Hagsater, Eric & Jimenez, Marco M., 2021, A new species of Epidendrum L. (Orchidaceae) of pendulous habit from Peru, PhytoKeys 184, pp. 55-66 : 55

Epidendrum lufinorum Ocupa & Hagsater 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).

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.

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.

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 ).

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 ).

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.

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.

Figures

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).

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).

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

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).

Figure 5. Other undescribed species of the Laxicaule Group found in Amazonas A, B, C Epidendrum aff. laxicaule sp. nov. and E. Epidendrum lufinorum D, E Epidendrum aff. megalopentadactylum sp. nov. Photographs by L. Pillaca (A, B, C) and L. Ocupa (D, E).