Pleurothallis velosana Sierra-Ariza & J.F.Rojas, 2025

Sierra-Ariza, Mario Alexei, Molina, Jhon Fredy Rojas & Wilson, Mark, 2025, Pleurothallis velosana (Orchidaceae: Pleurothallidinae), a new species from the eastern Andes of Colombia, Phytotaxa 715 (2), pp. 164-170 : 164-168

publication ID	https://doi.org/10.11646/phytotaxa.715.2.7
DOI	https://doi.org/10.5281/zenodo.17484639
persistent identifier	https://treatment.plazi.org/id/03F01A03-954E-FF91-03CB-F9FA31200013
treatment provided by	Felipe
scientific name	Pleurothallis velosana Sierra-Ariza & J.F.Rojas
status	sp. nov.

Treatment

Pleurothallis velosana Sierra-Ariza & J.F.Rojas , sp. nov. ( Fig. 1 View FIGURE 1 ).

Type:— COLOMBIA. Boyacá: Municipio de Arcabuco, Serranía del Peligro . 2670 m, 10 May 2025, Sierra-Ariza & Rojas Molina 543 ( holotype: TOLI) .

Pleurothallis velosana is most similar to Pleurothallis franciana Sierra-Ariza (2023: 36 ; Fig. 2 View FIGURE 2 ), but differs in having an oblong-triangular lip (vs. oblong-lanceolate), a cuspidate and involute apex (vs. acute and straight), a verrucose surface with scattered pustules (vs. vesiculose), and irregular margins and base of the lip with a spathulate glenion (vs. obovate) and two subtriangular, prominent lobes (vs. two round, less prominent lobes; Table 1 View TABLE 1 ).

Erect, epiphytic, caespitose herbs, 3.5–8.0 cm tall. Roots slender, 1.2 mm in diameter. Ramicauls green, 3.3–7.5 cm long, with two tubular sheaths on the basal half of the stem, light brown. Leaf light green, ovate-lanceolate, acuminate, 4.0–5.6 × 2.0– 2.5 cm, the base sessile, cordate. Inflorescence with a reduced peduncle, enclosed by a broad, reclining spathe ca. 6 mm long, bearing up to five flowers simultaneously; pseudopeduncle terete, green, 3.0–5.0 mm long; floral bracts tubular, acute, 3.0–4.0 mm long. Flowers with sepals and petals yellowish brown; lip reddish brown, with yellowish upper margins; column light yellow. Ovary yellow to red with black dots, papillate, pedicellate, cylindrical, longitudinal sulcate, 2.5 mm long. Sepals glandular-papillate, margins irregular. Dorsal sepal lanceolate, acute, 7.8–8.7 × 2.5–3.0 mm, 3-veined. Lateral sepals connate to form an ovate synsepal, rounded to bifid, concave at the center, with revolute margins and apex, 7.5–8.2 × 4.7–5.3 mm, 4-veined. Petals linear-triangular, slightly glandular-papillose, acute, with irregular margins, erose in the basal half, 3.2–3.7 × 0.6–0.8 mm, 1-veined. Lip oblong-triangular, apex cuspidate and involute, verrucose with scattered pustules, margin irregular to slightly erose, 3.3–3.6 × 1.4–1.7 mm, 3-veined; the base of the lip bears a small, spathulate glenion; base forming two subtriangular, prominent lobes. Column short, broad, semiterete, margins irregular, 0.8 × 1.2 mm, with a foot; stigma apical, bilobed. Anther cap yellow, apical, obovate, minutely papillose, 0.6 × 0.5 mm. Pollinia 2, yellow, obovoid. Capsule not seen.

Distribution and ecology:— Recorded in the Eastern Cordillera, municipality of Virolín, Santander Department, and municipality of Arcabuco, Boyacá Department, specifically in the Serranía del Peligro Regional Natural Park, at 2500–2800 m. Pleurothallis velosana grows as an understory epiphyte in well-preserved montane humid forests dominated by Quercus humboldtii Bonpland (1809: 155) , accompanied by other characteristic species such as Clusia multiflora Kunth (1822: 200) , Hedyosmum spp. , and Ocotea spp. It is primarily found at the base of large trees covered by dense layers of bryophytes and lichens in humid areas near water bodies, under medium to low light conditions. Populations are scattered, and individuals are rare and difficult to detect in their natural habitat.

Additional specimen examined:— COLOMBIA. Santander: Municipio de Charalá, centro poblado de Virolín , cuchilla del Fara , 2580 m, 11 May 2025, Sierra-Ariza & Rojas Molina 544 ( JBB) .

Phenology:— Flowering has been observed in January, May, July and November.

Conservation status:— Data deficient (DD). Pleurothallis velosana is a recently discovered species for which only five populations have been recorded in a single geographic area. It exhibits a restricted preliminary distribution, with an area of occupancy (AOO) estimated at 11 km ², and it is not possible to accurately estimate its extent of occurrence (EOO), suggesting that the species may face an elevated risk of extinction. Nevertheless, some populations are located in the jurisdiction of Serranía del Peligro Regional Natural Park, which provides a degree of protection in an officially protected area.

Eponymy:— In honour of Jorge Luis Velosa Ruiz, a renowned Colombian musician, composer, writer, professor, and veterinary doctor, in tribute to his invaluable legacy in the preservation and promotion of Colombian rural culture through his artistic works, social commitment and contribution to the cultural identity of Colombia.

Notes:— In addition to Pleurothallis franciana , the new species is also like Pleurothallis braidiana (Luer) Karremans (2019: 263) , Pleurothallis ariana-dayanae Vélez-Abarca, M.M.Jiménez & D.Gut. del Pozo (2022: 102) and Pleurothallis applanata Luer & Dalström (1996: 147) ( Table 1 View TABLE 1 ). Pleurothallis velosana and P. braidiana are from the Eastern Cordillera of the Colombian Andes, P. franciana in the Central Cordillera, and P. ariana-dayanae and P. applanata from Ecuador ( Fig. 5 View FIGURE 5 ). The new species has not been observed in sympatry with any of these species, and its restricted distribution, likely associated with specific elevational and ecological conditions, reinforces its independent status and provides additional support for its recognition ( Figs. 3 View FIGURE 3 , 4 View FIGURE 4 , Table 1 View TABLE 1 ). These species are readily recognizable from their morphology, particularly from the diagnostic features of the lip.