Epidendrum centralense, Quispe-Melgar, Harold Rusbelth, Llacua-Tineo, Elizabeth Santiago Ayala Yashira Stefani & Hágsater, Eric, 2023

Quispe-Melgar, Harold Rusbelth, Llacua-Tineo, Elizabeth Santiago Ayala Yashira Stefani & Hágsater, Eric, 2023, Synopsis of the Peruvian species of Epidendrum (Orchidaceae: Laeliinae) belonging to the Scabrum group, subgroup Soratae: diversity and description of a new species, Phytotaxa 603 (1), pp. 1-26 : 10-13

4. Epidendrum centralense E. Santiago, Hágsater, H.R.Quispe et Llacua, sp. nov. ( Figure 5 )

Type:— PERU. Junín: Huancayo Province, Santo Domingo de Acobamba District; Callanca locality, 3950 m, humid high elevation Andean Forest , epiphyte on Polylepis canoi , collected 06 November 2021, pressed 04 December 2021, H. R. Quispe 128 (holotype: HOXA! barcode: 080097) ( LCDP & photo voucher) .

S imilar to Epidendrum soratae but the leaves 2.0–2.5 × 1.0– 1.4 cm with the apex obtuse (vs. leaves 1.7–4.7 × 0.4– 0.8 cm with the apex sub-acute to acute), flowers green-brown with irregular red brown tinge (vs. flowers greenish yellow), the dorsal sepal oblong (vs. dorsal sepal narrowly ovate), the petals linear-oblanceolate (vs. petals linear), the column thin at the base with the cuniculus slightly inflated behind the perianth (vs. column progressively inflated at the base due to the prominent cuniculus clearly inflated on both sides of perianth), the cuniculus forming a small vesicle in pedicel (vs. cuniculus forming a prominent vesicle in pedicel), and the lip apex truncate (vs. lip with emarginate apex). ( Figure 6 ).

Description:— Epiphytic, erect to arching, monopodial, branching herb, ca. 48 cm tall. Roots 2–4 mm in diameter, from base of primary stem. Stems branching, cane-like, terete, thin; primary stem 12.5–16.5 × 0.3 cm; branches 8–16 × 0.2–0.3 cm; upper stems produced from a sub-apical internode of previous stem. Leaves 7 on primary stem, 4–6 on branches, distributed throughout stems, alternate, articulate, spreading with respect to stem, slightly arched, medium green, concolor; sheath 1.0 × 0.6–0.9 cm, tubular, striated and somewhat infundibuliform when dry; blade 2.0–2.5 × 1.0– 1.4 cm, lanceolate, obtuse, minutely apiculate, coriaceous, margin entire. Spathe lacking. Inflorescence 3.5 cm long (including flowers), apical, racemose, arching-nutant, flowers successive, densely few–flowered; peduncle 1.0– 1.2 cm long, laterally compressed, rachis slightly laterally compressed. Floral bracts 0.4–1.1 × 0.1–0.2 cm, half-length of ovary, except for lower bract which is considerably larger, narrowly triangular-lanceolate, acuminate, green with irregular red-brown dots, apex red-brown. Ovary 11 mm long, terete, thin, not inflated, slightly striated, spotted green to purple-brown. Flowers 8–12, successive, opening from base towards apex of inflorescence, resupinate, greenish brown with irregular red brown tinge, column turning yellow with age; fragrance not registered. Sepals spreading, free, apex obtuse, 3-veined, margin entire; dorsal sepal 5.6 × 2.1 mm, spatulate, apiculate, margin entire, slightly revolute; lateral sepals 6.3–6.6 × 2.7–2.9 mm, elliptic, apiculate, with a very prominent dorsal keel, margins entire, spreading. Petals 4.7–5.0 × 0.5–0.7 mm, spreading, free, linear-oblanceolate, 1-veined, margin entire, slightly revolute in basal half. Lip 3.6 × 6 mm, adnate to column, sub-entire, transversely reniform in outline, base cordate, apex obtuse, minutely emarginate, margins entire; bicallose, calli small, obovoid, parallel, 1.0 × 0.8 mm, separated by a thick mid-rib extending to apex of lip. Column 4.5 mm long, base thin, apex slightly dilated. Clinandrium-hood short, entire margin. Rostellum apical, split; viscarium semi-liquid. Lateral lobes of stigma small, occupying 1/3 length of stigmatic cavity. Cuniculus shallow, penetrating ovary just behind perianth, slightly inflated forming a short, incipient vesicle. Anther transversely ellipsoid, apex emarginate, front papillose, yellow, 4-celled. Pollinia 4, obovoid, laterally compressed; caudicles soft and granulose, twice as long as pollinia. Capsule 2.5–3.0 × 0.7–0.9 cm; pedicel 4 mm long, conical; body 1.0–1.7 × 0.7–0.9 cm, ellipsoid; apical neck 0.4–0.8 × 0.15 cm, thin. Finally, flowering time is in November.

Distribution and ecology: —Known presently only from the type, from central Peru, Department of Junín, in the upper part of the locality of Callanca. Located in the eastern mountain range of the central Peruvian Andes, within a humid forest dominated by Polylepis canoi and Polylepis argentea T.Boza & H.R.Quispe (2019: 327) . The environment is a typical high elevation Andean ecosystem surrounded by a matrix of grassland, lagoons and occasional snow, with the presence of other genera such as Gynoxys Cass. (1827: 455) , Buddleja L. (1753a: 112), and Lupinus L. (1753b: 721), at 3950 m elevation. ( Figure 7 ).

Etymology: —The epithet name refers to the department of Junín, located in the central region of Peru, where the species has been collected.

Notes: —Comparisons were made with the species of the subgroup that grow in Junín, as well as closely related species comparing with the type material of E. fruticulus Schltr. (1921: 84) , E. physopus Kraenzl. (1905: 87) , E. monteagudoi Hágsater & E. Santiago (2013: t. 1459), E. jose-alvarezii Hágsater, Gut.Peralta & Nauray (2015: t. 1531) and E. soratae Rchb.f. (1878b: 24) (images of type and live material at MO and USM, as well as descriptions); these species being most similar to the new species. Epidendrum fruticulus has yellow flowers, the lateral sepals red-brown, and the lip deeply 3-lobed. Epidendrum physopus has green to yellow-green flowers, the lip deeply 3- lobed. Epidendrum monteagudoi has cream colored flowers, sometimes with vinaceous spots, and the lip is shallowly 3-lobed, the mid-lobe small, widely triangular, obtuse. Epidendrum jose-alvarezii has carmine-red flowers, the lip transversely reniform, with lateral lobes dolabriform-orbicular, with the mid-lobe incipient, emarginate. Epidendrum soratae is the most similar species and is discussed in the diagnosis.

Conservation Status:— DD. Data deficient. Known presently only from the type .

Figures

FIGURE 5. Plate of Epidendrum centralense. A. Habit. B. Inflorescence C. Flower, lateral view. D. Dissected perianth.E-G. Column and ovary, ventral, lateral and dissected view. H. Anthercap and pollinarium. I. Capsule. Photographs and LCDP by Harold Rusbelth Quispe- Melgar from the type, H.R. Quispe 128.

FIGURE 6. Comparison between Epidendrum centralense (A) and Epidendrum soratae (B). The most obvious difference clearly visible in images of the flowers is the swollen vesicle, which starts at the base of the column in E. soratae, and behind the perianth in E. centralense. Photographs by Harold Rusbelth Quispe-Melgar.

FIGURE 7. Epidendrum centralense. A. Plant. B. Inflorescence. C. Habitat. Photographs by Harold Rusbelth Quispe-Melgar.