Lepanthes vespertina Bogarín, M.Rodríguez & L.Ulloa, 2025

Bogarín, Diego, Rodríguez-Cáceres, Marisol & Ulloa-Vargas, Lisseth, 2025, Lepanthes vespertina (Orchidaceae: Pleurothallidinae), a new species from Costa Rica, Phytotaxa 714 (3), pp. 237-245 : 238-243

Lepanthes vespertina Bogarín, M.Rodríguez & L.Ulloa , sp. nov. ( Figs 1–5 )

Type:— COSTA RICA. Cartago: Turrialba, Tayutic , camino entre Tuis y Platanillo , entrada hacia el Hotel Rivel , calle Rivel, orillas del río Tuis , 9°48’22.72” N 83°35’00.04” W, 999 m, bosque muy húmedo premontano , epífita en bosque secundario , 29 Jul 2024, preparado el 21 marzo 2025, Bogarín 15208, Camacho, Ulloa & Villalobos ( holotype: JBL; isotype, JBL-spirit) .

Lepanthes vespertina resembles L. umbonifera in its denticulate sepals and bilobed petals, with the upper lobe about three times wider than the lower. However, it differs by its entire, bilaminate lip with obovate blades that embrace the column and converge beneath its apex ( vs. umbonate, ovate, straight blades in L. umbonifera that remain separate. The lip appendix of L. vespertina is also distinctive, being pubescent and cylindrical, terminating in a bifid, ciliate membrane ( vs. minutely ciliate, inconspicuous, and apiculate in L. umbonifera ).

Erect, epiphytic, caespitose herbs, up to 5 cm tall. Roots filiform, flexuous, to 0.2–0.6 mm in diameter. Ramicauls slender, erect, 1.6–3.0 cm long, enclosed by 4 to 6 adpressed, ribbed, lepanthiform sheaths 3.0–6.0 mm, dilated at the apex into obliquely lanceolate, attenuate ostia. Leaves lanceolate, coriaceous, slightly convex, green to purple on the adaxial and abaxial surface, with green parallel veins, 2.0–2.5 × 1.0– 1.3 cm, obtuse, conduplicate, retuse at the apex, with the midvein ending in a short apicule in the abaxial sinus. Inflorescence composed of an abbreviated main stem, successive, distichous, multi-flowered, shorter than the leaves, 1.5–2.0 cm long, each bearing approximately 8 flowers opening successively, the flowers positioned on the adaxial surface of the leaf; peduncle extremely abbreviated, concealed mainly by the upper lepanthiform bract; pseudopeduncle filiform, terete, 0.9–1.1 cm long, composed of several internodes, enclosed by two tightly adpressed, tubular, sparsely muricate, acute bracts up to 1.0 mm long; rachis zig-zag, 4.0–5.0 mm long; floral bracts acute, transversely ovate, 0.5–0.8 mm long. Pedicels terete 0.8–12.5 mm long, persistent. Flowers 3.0– 3.5 mm in diameter, brightly coloured. Ovary cylindrical, ridged, 0.9 mm long. Dorsal sepal purplish red, ovate, acute to acuminate, denticulate, 2.7–4.2 × 1.6–2.3 mm, connate to lateral sepals for 1.0– 1.2 mm. Lateral sepals green, ovate, acute to acuminate, denticulate, connate, 2.6–3.5 × 1.5–2.0 mm. Petals rubyred proximally, 0.4–0.5 × 1.8–2.0 mm, bilobed, upper lobe obovate 0.8 – 0.9 × 1.3–1.5 mm, the lower lobe oblong, minute, 0.30–0.40 × 0.35–0.40 mm. Lip bilaminate, the middle margin encircling the column, blades obovate, 0.5–0.8 × 1.2–1.3 mm extended, with apices converging beneath the column, connectives cylindrical, to 0.5 mm, appendix pubescent, cylindrical with a bifid membrane to 0.15–0.20 mm long. Column terete, violet, broader at the apex, to 0.9–1.0 mm long. Anther cap light purple, cucullate, triangular, 2–celled, to 0.5 mm, the anther dorsal and the stigma apical. Pollinia two, 2, 0.5 mm, obpyriform, attenuate at the base, viscidium round, apical yellowish.

Distribution and ecology:— Found on the Caribbean slope of the Cordillera de Talamanca. The type locality is in the Tausito Biological Reserve, Pejibaye. Another collection was made along the Tuis River near Tayutic, on the road between Tuis and Platanillo, Turrialba, Cartago. It is found as an epiphyte in secondary forests, premontane rainforests and premontane wet rainforests around 1000 meters ( Fig. 4 ).

Phenology:— Flowering all year in cultivation. In the field, flowering was observed in April, July and August.

Etymology:— Derived from the Latin vespertinus, belonging to the evening, and referring to the colour of the petals, which are like those of a sunset.

Conservation status:— Known from only two locations. Following the IUCN Red List criteria (2022), the species should be considered data deficient (DD) until further field studies provide sufficient information to evaluate its conservation status.

Additional specimen examined:— COSTA RICA. Cartago: Jiménez, Pejibaye, Tausito , Reserva Biológica , cerca de las instalaciones de la estación , 9°47’02.7”N 83°45’04.3”W, 1020 m, bosque pluvial premontano , epífitas, recolectada por Daniel Jiménez, 25 Apr 2013, Bogarín 10127 ( JBL! -spirit; Fig. 2 ) .

Notes:— Lepanthes vespertina and L. subdimidiata Ames & Schweinfurth (38: 1925) are both found in the Pejibaye region, but the exact location of L. umbonifera remains unknown. Nonetheless, all three species are endemic to Costa Rica. Vegetatively, L. vespertina closely resembles both L. umbonifera and L. subdimidiata ( Table 1 ); for example, all three have slender ramicauls. However, L. vespertina is the smallest, with ramicauls up to 3 cm long and leaves up to 2.5 cm long (compared to ramicauls over 3.5 cm and leaves over 2.7 cm in L. umbonifera ).

Over the past twenty years, the taxonomy of Lepanthes in Costa Rica has advanced through the combined use of type specimens, detailed botanical illustrations, measurements of species’ morphological variation, and ongoing fieldwork. This has resulted in a species count of 165, with around 70 new species added in the last 25 years ( Pupulin et al. 2023). These efforts have clarified species complexes with similar morphologies ( Pupulin & Bogarín 2010) and have been further refined by applying next-generation sequencing to resolve phylogenetic relationships in specific groups ( Bogarín et al. 2018). However, several species originally described by Luer based on specimens collected by Endrés in the 19th century, such as L. dotae Endrés in Luer (143: 1995), L. dichroma Luer (59: 1996), L. fulgiens Luer (151: 1995), L. hamulifera Luer (156: 1995), L. limbellata Endrés in Luer (159: 1995), L. selliana Endrés in Luer (167: 1995), L. similis Luer (64: 1996) and L. umbonifera , remain poorly known and undocumented using modern methods. Despite the lack of recent collections for many of these taxa, Endrés’s detailed illustrations still provide a valuable foundation for assessing these names.

Figures

FIGURE 1. Lepanthes vespertina. A. Habit. B. Flower. C. Perianth, flattened. D. Ovary, column and lip, lateral view. E. Lip, spread. F. Pollinarium and anther cap. Drawn from Bogarín 15208 by L. Ulloa.

FIGURE 2. Lepanthes vespertina. A. Habit. B. Flower. C. Perianth, flattened. D. Ovary, column and lip, lateral view. E. Lip, spread. Drawn from Bogarín 10127 by D. Bogarín and L. Ulloa.

FIGURE 3. Comparison of flower morphology. A–D. Lepanthes umbonifera; E–H. Lepanthes vespertina. A. Flower, front view. B. Flower, side view. C. Column apex and lip, front view. D. Lip appendix, front view. Based on Endrés’s original illustrations, W! 0019415, W! 0019417, W! 0019300. A. Flower, front view. B. Flower, side view. C. Column apex and lip, front view. D. Lip appendix, front view. Drawing based on the holotype of L. vespertina by L. Ulloa.

FIGURE 4. Distribution of Lepanthes vespertina. Species distribution plotted on a modified version of an exaggerated relief map of Costa Rica, originally by Guzmán Q. (2021). Used under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/).The original map was adapted by adding points indicating species occurrences. Map by D. Bogarín and L. Ulloa.

FIGURE 5. Flower morphology of Lepanthes vespertina based on the plant that became the holotype. Photo by D. Bogarín.