Pleurothallis winkeliana Karremans, Bogarín & Pupulin, 2025

Karremans, Adam P., Pupulin, Franco, Gange, John & Bogarín, Diego, 2025, Three new species of Pleurothallis (Orchidaceae) from Costa Rica and Panama, with a note on asexual reproduction by prolification in Pleurothallidinae, PhytoKeys 256, pp. 197-220 : 197-220

Pleurothallis winkeliana Karremans, Bogarín & Pupulin sp. nov.

Type.

Costa Rica. • Puntarenas: Coto Brus, Sabalito, Zona Protectora Las Tablas, 13 km al noreste de Lucha, Sitio Coto Brus, entre Río Surá y Quebrada Sutú, Finca de Miguel Sandí , 8°56'46.1"N, 82°44'30.9"W, 1778 m, bosque pluvial montano bajo, epífita en potreros arbolados, 20 April 2012, fl. in cult. 25 June 2012, A. P. Karremans & J. Geml 5403 (holotype: JBL - spirit, E 0966 !; Figs 8 , 9 A – E ) .

Diagnosis.

Morphologically closely resembling P. longipetala Bogarín & Belfort , but distinguished by the occasionally prolific plant that produces clumps of ramicauls (vs. non-prolific), the proportionally broader (ratio length: width = 2: 1 vs 3: 1) leaves, cordate in shape (vs. narrowly ovate-lanceolate) with overlapping basal lobes (vs. basal lobes non-overlapping), the smaller flower (<1.5 vs> 2. 0 cm), the shorter and narrower petals (5.4–5.7 × 0.7–0.8 vs. 7.9–8.6 × 1.6–1.7 mm) and by the lip, which is pendent and perpendicular to the column (vs erect, parallel to the column), and obscurely glandular (vs. thickly verrucose).

Description.

Epiphytic, caespitose, occasionally prolific, erect to suberect herb, up to 25 cm tall. Roots flexuous, thin, ca. 1 mm in diameter, densely spaced, appearing fasciculate. Primary ramicauls erect to suberect, slender, up to 9.0–23.0 cm long, with 2 tubular, tightly adpressed, papyraceous sheaths, up to 2.5–4.3 cm long, one close to the base, and another reaching the middle of the ramicaul. Secondary ramicauls 1.0– 3.5 cm long, produced profusely from the floral meristem on the apex of primary ramicaul, being able to produce clumps of multiple ramicauls before severing naturally. Leaves horizontal to suberect, coriaceous, sessile, cordate, acute, with the basal lobes confluent to overlapping. Blades of primary ramicauls 4.0–9.6 × 1.5–4.0 cm, blades on secondary ramicauls 1.5–5.4 × 0.6–1.7 cm. Inflorescences persistent, forming successive multi-flowered coflorescences with a single open flower, subtended by a nearly prostrate or suberect spathe which appears deeply torn over time, ca. 1 cm long; pedicels terete, pale gray-yellow, with irregular black flecks. Ovary slightly clavate, bent, 3.0– 3.2 mm long, green, with occasional black dots. Flowers spreading, transparent purple, with dark purple petals and lip, a whitish column, suffused with pink, and a yellowish anther cap. Dorsal sepal elliptic, acute, 3 - veined, 8.5 × 4.0– 4.2 mm. Lateral sepals connate in a narrowly ovate synsepal, acute, 4 - veined, 7.3–7.8 × 4.7–4.8 mm. Petals linear, oblique, acute, 1 - veined, 5.4–5.7 × 0.7–0.8 mm, with glandular margins. Lip triangular-ovate, resting on the synsepal, 2.6–2.8 × 2.3 mm, blade glandular, margins glandular-erose, acute, shortly apiculate, glenion a deep, oblong basal cavity. Column straight, transversely subrectangular, ca. 1.5 mm long, with a very short, glandular column foot, the anther and stigma apical. Anther cap ovate, cucullate, obtuse, 2 - celled. Pollinarium composed of 2, narrowly ovate-pyriform pollinia, connected to a liquid, drop-like viscidium. Fruits and seeds unknown. This description is based on A. P. Karremans & J. Geml 5403.

Additional specimens examined.

Costa Rica. • Limón: Talamanca, Telire. Cordillera de Talamanca, Parque Internacional La Amistad (ACLA-C), sendero de la transtalamanca, bajando de la Fila Bugú hacia el Río Tapari , 09°26'48.00"N, 83°11'12.00"W, 1380 m, bosque pluvial premontano, bosque primario, epífita, a media luz, collected 27 April 2017, I. Chinchilla 3408, A. P. Karremans, G. Rojas-Alvarado, M. Cedeño, E. Kaes & O. Zúñiga [ JBL - spirit, J 0784 ! (prepared 14 May 2018), A 0366 ! (prepared 2 May 2019)] . • Puntarenas: Buenos Aires, Potrero Grande, Altamira , Parque Internacional La Amistad, Sector Altamira, sendero al Valle del Silencio, cerca Cerro Hoffman , 9°04'56.2"N, 82°58'36.4"W, 2347 m, bosque pluvial montano, 30 August 2011, D. Bogarín 9138 & A. P. Karremans (Fig. 9 F ) . Same locality and date, D. Bogarín 9140 & A. P. Karremans (Fig. 9 F ) . • Puntarenas: Coto Brus, Sabalito, Zona Protectora Las Tablas, 13 km al noreste de Lucha, Sitio Coto Brus, entre Río Surá y Quebrada Sutú, Finca de Miguel Sandí , 8°56'46.1"N, 82°44'30.9"W, 1778 m, bosque pluvial montano bajo, epífita en potreros arbolados, collected 20 April 2012, A. P. Karremans & J. Geml 5403 ( JBL - D 6595 ! (prepared 9 January 2015), JBL - A 0237 ! (prepared 29 November 2018), JBL - A 0250 ! (prepared 21 February 2019), JBL - J 1024 ! (prepared 12 July 2016).

Eponymy.

Honoring Dutch botanist Gab van Winkel (1955–2023), late editor of Orchideeën, journal of the Dutch Orchid Society (Nederlandse Orchideeën Vereniging), and director of the official website of the European Orchid Council (EOC). Gab has been recognized for devoting his life to the study of orchids ( Anghelescu et al. 2024), and his untimely passing has been a great loss.

Phenology.

Flowering of P. winkeliana has been recorded from November to July, mostly corresponding to the dry season in Costa Rica.

Distribution and ecology.

Currently known only from the southern Cordillera de Talamanca in Costa Rica, where plants grow epiphytically in primary forests at around 1400–2300 m of elevation. Pleurothallis winkeliana appears to be rare but is found on both watersheds of the Cordillera de Talamanca in southern Costa Rica, close to the Panamanian border, where it has been recorded in the neighboring Limón and Puntarenas provinces.

Notes.

Pleurothallis winkeliana belongs to the P. phyllocardia assemblage (sensu Pupulin et al. 2021), characterized by presenting mostly narrow leaves, an erect to suberect, non prostrate spathaceous bract [except in P. adventurae Karremans & Bogarín ( Karremans and Bogarín 2011: 112) ], and coriaceous flowers that remain open after anthesis. In Costa Rica, this assemblage includes 13 species and a natural hybrid. Pleurothallis winkeliana is most similar to P. longipetala , which was described from Tapantí in central Costa Rica, growing at an elevation of 1453 m. From the latter, P. winkeliana is mostly distinguished by the taller habit, and by its frequently prolific stems, that are topped by comparatively broad (ratio length: width = 2: 1 vs 3: 1) cordate leaves (vs. narrowly ovate-lanceolate), which bear overlapping (vs. non-overlapping) basal lobes. The flowers of Pleurothallis winkeliana are smaller, with the smaller petals (5.4–5.7 × 0.7–0.8 vs. 7.9–8.6 × 1.6–1.7 mm), distinctly narrower at the base (vs. broadened at the base), and the lip is geniculate at the base and held perpendicularly to the column (vs. straight, parallel), with the blade obscurely glandular (vs. thick verrucose). The new species is also reminiscent of Pleurothallis anthurioides A. Doucette from Costa Rica and Panama ( Pupulin et al. 2021), but the flowers are much smaller (e. g. sepal length 7.3–8.5 vs. 12–19 mm, petals 5.4–5.7 × 0.7–0.8 vs. 10–13 × 3–4 mm), the petals are linear (vs. oblong) and the lip triangular-ovate (vs. oblong-peltate).

Figures

Figure 8. Pleurothallis winkeliana Karremans, Bogarín & Pupulin A habit showing some prolific vegetative growths B flower C dissected perianth (dorsal sepal, two lateral petals, two lateral sepals fused into a synsepal and a view of the lip) D two views of the lip E column and lip, lateral view F column and ovary, ventral, dorsal and lateral views G anther cap and two views of the pollinarium. LCDP prepared by FP based on Karremans 5403.

Figure 9. Pleurothallis winkeliana Karremans, Bogarín & Pupulin showing some floral variation A – E Karremans 5403 F Bogarín 9138 G Bogarín 9140. Photographs by the authors.