Lepanthes gibbosa Bogarín, S.Lara & Y.Camacho, 2025

Bogarín, Diego, Lara-Guerrero, Sofia & Camacho-Solis, Yesly, 2025, Lepanthes gibbosa (Orchidaceae: Pleurothallidinae), a new species from Costa Rica, Phytotaxa 714 (4), pp. 281-291 : 283-288

Lepanthes gibbosa Bogarín, S.Lara & Y.Camacho , sp. nov. ( Figures. 1–4 )

Type:— COSTA RICA. Alajuela: Alfaro Ruiz, Distr. La Palmira, Pueblo Nuevo , road to Los Bajos del Toro , 2050 m, lower montane wet forest secondary and remnants of primary vegetation , 30 August 2001, F. Pupulin 3282, M. Pupulin, C. Pupulin & D. Castelfranco ( holotype: JBL-spirit; isotype, JBL-spirit) .

Lepanthes gibbosa differs from L. mentosa by its petals with upper lobes longer than the lower lobes and convergent ( vs. subequal and not convergent), and by its lip with oblong-ovate lobes, 1.0– 1.3 mm long ( vs. obovate, 1 mm long), bearing an external, subquadrate, slightly reflexed appendix ( vs. small, oblong, straight appendix). In L. gibbosa , the thick lip body conceals the column in frontal view ( vs. conspicuous, remains visible).

Description:— Epiphytic, cespitose, erect herb to 6.0– 9.5 cm tall. Roots filiform, flexuous, to 1 mm in diameter. Ramicauls slender, erect or pendent, to 4.0– 6.6 cm long, covered by 6–11, tightly adpressed, muriculate, brownishwhitish lepanthiform sheets, dilated at the apex into an obliquely, lanceolate, ciliate ostia, to 6 mm long. Leaves ovate-elliptic, thick, flat, conduplicate, 1.0–2.7 × 0.8–1.6 cm, adaxially green, abaxially purple, the base rounded, abruptly contracted into a short, petiole to 2.0 mm long, the apex obtuse, shortly cuspidate, excise, with the tip of the central vein protruding abaxially within the sinus, appearing tridentate. Inflorescence composed of abbreviated main florescence with successively multi-flowered coflorescences up to 2.6 cm long, each bearing approximately eight flowers opening successively at once, predominantly developing on the abaxial side of the leaf; peduncle extremely abbreviated, mostly concealed by the upper lepanthiform bract; pseudopeduncle filiform, terete, 5.0–6.0 mm long, composed of several internodes, enclosed by two tightly adpressed, tubular, sparsely muriculate, acute bracts up to 1 mm long; rachis fractiflex, up to 2.0 cm long; floral bracts lanceolate, acute, sparsely muriculate, to 1 mm long. Pedicels 2 mm long, persistent, at least eight on each inflorescence. Flowers yellowish-white, the dorsal sepal red veins stained with red at the apex, the petals orange with an inner red stain, the column and lip red, and the anther cap purple. Ovary to 1.0– 1.5 mm long, with prominent, slightly denticulate ribs. Dorsal sepal ovate, 3-veined, dorsally carinate-denticulate, acute to acuminate, sparsely denticulate, concave, 4.0–4.5 × 2.1–2.8 mm, connate with the lateral sepals for about 0.9 mm. Lateral sepals ovate, 2-veined, dorsally carinate-denticulate, sparsely denticulate, acute to acuminate, 5.0 × 2.0 mm, connate at the base for about 3.3–4.2 × 1.5–2.1 mm. Petals transversely bilobed, cellular pubescent, ciliate, 0.4–0.7 × 1.6–2.5 mm, the upper lobes oblong, obtuse to subtruncate, the lower lobes ovate, acute, smaller than the upper lobe. Lip bilaminate, cellular pubescent, ciliate, rounded in general outline, 1.0–1.3 × 1.6–1.9 mm, the lobes oblong-ovate, rounded at the base, suberect, the basal margins superposed and completely encircling the column, the apices converging, obtuse, falcate; connectives oblong, pubescent; the lip body oblong, rounded, appendix external, subquadrate laterally, rounded when expanded, pubescent, slightly reflexed. Column terete, broadened at the subspheric apex, 1.3 mm long, the anther and the stigma apical. Anther cap cucullate, ovate, 2-celled, about 1.5 mm long. Pollinia two, obpyriform, yellow, with filamentous stipes; viscidium rounded, orange, apical.

Distribution and ecology:— This species is exclusively found in Costa Rica, specifically along the Cordillera Volcánica Central and the Cerros de Escazú, including Pico Blanco in the Cordillera de Talamanca. It thrives in both primary and secondary forests, often found in clearings, on lianas, or on solitary trees within pastures or mature forests of lower montane rainforests between 1,608 and 2,271 meters ( Figure 3 ), where it grows alongside characteristic montane tree species such as Arachnothryx buddleioides ( Bentham 1839 –1857: 69) Planchon (1849: 442) ( Rubiaceae ), Guarea macrocarpa de Candolle (1905: 420) ( Meliaceae ), Ocotea praetermissa van der Werff (1996: 482) ( Lauraceae ), Oreopanax nubigenus Standley (1927: 315) ( Araliaceae ), Persea schiedeana Nees (1836: 130) ( Lauraceae ), Quercus bumelioides Liebmann (1854: 188) ( Fagaceae ), and Quercus salicifolia Née (1801: 265) ( Fagaceae ). Flowers were observed throughout the year in cultivated plants and from July to November in herbarium specimens, indicating potential flowering peaks during these months. Fruiting was not observed.

Etymology:— The specific epithet comes from the Latin gibbosus, meaning hunch-backed, which refers to the notably concave dorsal sepal, one of the features that distinguishes this species from its morphologically closest relatives.

Preliminary conservation remarks:— This species is currently known from four locations in Costa Rica, specifically in the Cordillera Volcánica Central and Cerros de Escazú, at the foothills of the Cordillera de Talamanca. Based on seven records, we calculate an Area of Occupancy (AOO) of 20 km ² and an Extent of Occurrence (EOO) of 532.3 km ², values that would fall within the thresholds of the Endangered (EN) category under IUCN Criterion B. However, these values alone are insufficient to propose a formal Red List assessment, as Criterion B also requires the evaluation of at least two subcriteria (a: severe fragmentation or limited number of locations; b: continuing decline; c: extreme fluctuations), for which data are currently lacking. Potential threats include habitat fragmentation, deforestation, land conversion for agriculture in the Cordillera Volcánica Central, and urban expansion near the city of San José within the Cerros de Escazú. Habitat degradation and climate change may also pose additional risks.Although the species occurs at the boundaries of Braulio Carrillo and Juan Castro Blanco National Parks, as well as within the Cerros de Escazú Protective Zone, the effectiveness of these protected areas in securing long-term population viability remains to be assessed. A comprehensive evaluation of potential threats will be necessary to determine the appropriate conservation status once additional data become available following its recognition as a distinct taxon.

Additional specimens examined:— COSTA RICA. Alajuela: Alfaro Ruiz, Palmira district , Pueblo Nuevo , La Picada , highway to Bajo del Toro , 2050 m, lower montane forest , remnants of primary forest in pastures , 21 November 1999, F. Pupulin 1764, L. Spadari, S. Méndez & V. Blanco M. ( USJ). Alajuela: San Carlos, Quesada , around 5 km east from Sucre, west limit of the Juan Castro Blanco National Park , slopes of Cerro Platanar , 10°15’28.3”N 84°21’58.15”W, 1608, lower montane rain forest , epiphytes in wooded pastures , 18 July 2015, D. Bogarín 11805 & J. de La Cruz (JBL-spirit) ( Figure 4A ). Heredia: Braulio Carrillo National Park, 10°10’40”N 84°07’00”W, 2100, in primary forest 0.5–1 km NE of Refugio, epiphytic on liana in primary forest near gap , 4 November 1990, S.W. Ingram & K. Ferrell-Ingram 668 ( CR!, MO). San José, Escazú, top area of Cerro Pico Blanco , 2100–2271 m, 9°52’34”N 84°8’5” W, lower montane very humid tropical forest , epiphytes in young secondary forest with remnants of primary forest , 5 July 2003, D. Bogarín 270 & A. Granados ( JBL-spirit). Escazú, San Antonio , Zona Protectora Cerros de Escazú , Pico Blanco and surroundings , 9.873 N, 84.149 W, ca. 2200 m mature cloud forest , with tree species such as Persea schiedeana Nees (1836: 130) , Ocotea praetermissa van der Werff (1996: 482) , Quercus salicifolia Née (1801: 265) , Quercus bumelioides Liebmann (1854: 188) , Oreopanax nubigenus Standley (1927: 315) , Guarea macrocarpa de Candolle (1905: 420) , Arachnothryx buddleioides ( Bentham 1839 –1857: 69) Planchon (1849: 442), 25 November 2021, L. Álvarez 591 ( JBL-spirit). Same locality, L. Álvarez 592 (JBL-spirit) ( Figs. 2A, 2B ) .

Taxonomic discussion: When describing L. demissa from a collection in Chiriquí, Panama, Luer (1984) did not include illustrations in the protologue, which complicates the accurate interpretation of this species ( Figure 5 ). Lepanthes demissa was recorded in Costa Rica from the Cordillera Volcánica Central by Pupulin (2002) ( Pupulin et al. 1764, USJ!) and Luer (2003), ( S.W. Ingram 668, CR!, MO), and from the southern region of the Cordillera de Talamanca ( D. Bogarín 8414, JBL!) by Pupulin et al. (2023) ( Figure 4B ). However, after examining the drawing of the type of L. demissa at SEL and verifying the characteristics of the plant from the type specimen and the protologue, we concluded that the specimens cited by Pupulin (2002) and Luer (2003) from the Cordillera Volcánica Central are more morphologically similar to the concept of L. gibbosa , as proposed here.

Lepanthes demissa is most similar to L. gibbosa and L. mentosa , sharing ovate, denticulate sepals, oblong petals, and a bilaminate lip with obovate blades ( Table 1 ). It differs by the pendent habit ( vs. erect to suberect), the longer, weak ramicauls up to 9.5 cm ( vs. shorter < 6.6 cm), the narrowly ovate, acuminate leaves 3.5–5.5 cm long ( vs. ovate, acute leaves to 2.7 and 2.3 cm long in L. gibbosa and L. mentosa , respectively). The petals are narrowly oblong ( vs. oblong in L. gibbosa and L. mentosa ). The lip is narrowly oblong with a small round cavity, inconspicuous lip body, and pedunculated appendix ( vs. oblong-ovate with a reflexed, rounded lip body and subquadrate appendix in L. gibbosa ; or obovate with a prominently protuberant, thick lip body and oblong appendix in L. mentosa ) ( Figure 4 ).

Lepanthes gibbosa differs from L. mentosa by its longer ramicauls, 4.0– 6.6 cm ( vs. 1.5–4.0 cm), longer coflorescences up to 2.6 cm long ( vs. < 0.5 cm), and flower coloration (yellowish-white flowers with red veins and orange petals marked with a distinctive red spot vs. reddish flowers with orange petals tinged with red). The petals of L. gibbosa have oblong upper lobes that are longer than the oblong-ovate lower lobes and are convergent ( vs. oblong, subequal, and non-convergent in L. mentosa ). The lip of L. gibbosa bears a thick body that conceals the column in frontal view, with an external, oblong, subquadrate, slightly reflexed appendix ( vs. a thicker, chin-like, prominently protuberant lip body that remains visible in frontal view, with an oblong appendix in L. mentosa ).

Lepanthes mentosa is limited to the Monteverde region within the Cordillera de Tilarán, at elevations between 1,400 and 1,818 meters. In contrast, L. gibbosa occurs in the Cordillera Volcánica Central and the montane forests of the lower northwestern Cordillera de Talamanca, especially in the Cerros de Escazú area, at elevations ranging from 1,600 to 2,300 meters. Luer (2003) mentioned the specimen S.W. Ingram 1519 (MO) for L. mentosa as coming from the Cerro de la Muerte region along the Cordillera de Talamanca; however, this specimen was actually collected in the Monteverde reserve, which is consistent with the known distribution of L. mentosa ( Tropicos 2025) . Finally, L. demissa is restricted in Costa Rica to the southern Pacific watershed of the Cordillera de Talamanca, near the border with Panama ( Pupulin et al. 2023) ( Figure 3 ).

Conservation efforts should focus on ongoing fieldwork to verify the presence of L. gibbosa populations in other protected areas, such as Juan Castro Blanco National Park and the Monteverde Cloud Forest Reserve, along with long-term population monitoring for its official conservation assessment. Moreover, we emphasize the importance of in situ- based alpha taxonomy and access to type specimens and protologues, which have historically been unavailable in many biodiverse countries but are now increasingly accessible as digital documents ( Pupulin 2016). These resources were crucial in determining the identity of L. demissa in Costa Rica and in identifying L. gibbosa as a new species, distinct from L. mentosa .

Figures

FIGURE 1. Lepanthes gibbosa. A. Habit. B. Flower in ¾ view. C. Ovary, column with lip in lateral view. D. Dissected perianth. E. Lip, spread. Drawing credits: D. Bogarín and S. Lara from the holotype.

FIGURE 2. Comparison of flowers of A-B Lepanthes gibbosa A. (L. Álvarez 592, JBL). B. (L. Álvarez 591, JBL) and C-D Lepanthes mentosa C. (JBL-37387, JBL). D. (JBL-44506, JBL). Scale bar = 3 mm. Photo credits: Y. Camacho & S. Lara.

FIGURE 3. Distribution map of Lepanthes gibbosa (white), L. demissa (red), and L. mentosa (yellow) in Costa Rica based on herbarium records. Map credits: S. Lara.

FIGURE 4. Flower morphology of A. Lepanthes gibbosa (D. Bogarín 11805, JBL) B. Lepanthes demissa (D. Bogarín 8414, JBL). C. Lepanthes mentosa (D. Bogarín 11533, JBL).

FIGURE 5. Lepanthes demissa A. Habit. B. Flower in ¾ view. C. Ovary, column with lip in lateral view. D. Dissected perianth. E. Column apex and lip, front view. Redrawn from the original Luer´s holotype illustration by D. Bogarín (C. Luer et al. 9292, SEL). Drawing credits: D. Bogarín.