Abstract

Pleurothallis markgruinii, a particularly tall species for the genus, is described as new to science and an illustration provided. The new species is most similar to Pleurothallis gargantua and shares with that species its large size, reaching 1 m tall, but differs in the much smaller flowers with a deeply concave dorsal sepal, narrower petals, and a synsepal with strongly revolute margins that form an elongated, triangular shape. Comprehensive field research has shown Pleurothallis markgruinii to have a restricted geographical range in the northwest Andes of Ecuador, and it is assessed as Critically Endangered.

Keywords: Carchi, Dracula Reserve, New orchid species, Reserva youth land trust

Composite dissection plate for Pleurothallis markgruinii Baquero & M.F.Monteros, sp. nov.  A, Habit; B1, flower, frontal view; B2, flower, lateral view; C, dissected perianth; D1, lip and column, lateral view; D2, lip and column, dorsal view with magnified image showing the rugulose-verrucose texture of the lip; E, capsule, dorsal view. Photographs: Marco F. Monteros.

Pleurothallis markgruinii Baquero & M.F. Monteros, sp. nov.

This new species is most similar to Pleurothallis gargantua in the large size of the plants (up to 1 m tall) and the large flowers (among the largest in the genus, between 5.6 and 10 cm long) borne at the base of a large (up to 30 cm long) ovate leaf, but it differs from that species in its considerably smaller flowers, 6.1 cm (vs 10.5 cm long when …

Etymology. Named in memory of Mark Gruin, horticulturist, curator at Zoo America, and benefactor at the Rainforest Trust, who devoted the bulk of his life’s work to protecting nature and supporting budding conservationists.

L. E. Baquero, M. F. Monteros, G. A. Iturralde, M. M. Jimenez and R. Dueñas. 2024. PLEUROTHALLIS MARKGRUINII, A NEW PLEUROTHALLIDINAE(ORCHIDACEAE) FROM NORTHWESTERN ECUADOR. Edinburgh Journal of Botany. 81; DOI: 10.24823/ejb.2024.2032   journals.RBGE.org.uk/EJB/article/view/2032 

Pleurothallis markgruinii, una especie con plantas particularmente largas dentro del género se describe e ilustra aquí como nueva para la ciencia. La nueva especie es similar a Pleurothallis gargantua y comparte con esta las grandes plantas que alcanzan 1 m en longitud, pero se diferencia en las flores mucho más pequeñas con el sépalo dorsal muy cóncavo, pétalos más estrechos, y un sinsépalo con márgenes fuertemente revolutos que le dan una forma alargada y triangular. Investigación de campo exhaustiva muestra que Pleurothallis markgruinii tiene una distribución restringida, al noroeste de los Andes en Ecuador y es evaluada como en peligro crítico.