DOI: 10.5091/plecevo.175775

Authors: Daniel B. Montesinos-Tubée, Cameron E.L. Dasher, Thomas Borsch, Alejandro Torres-Montúfar

Abstract: Background and aims – The newly described species Arcytophyllum leymebambense sp. nov. (Rubiaceae) from the Amazonas department of northern Peru represents an isolated lineage within the monophyletic genus Arcytophyllum. This study aims to describe its distinctive morphological features and ecological context, assess its phylogenetic position, and discuss its implications for the diversification of the genus in the Andes. Material and methods – Morphological observations were conducted on herbarium specimens and field collections from the type locality. Phylogenetic analyses were performed using nuclear and plastid DNA sequences from the tribe Spermacoceae, with particular emphasis on Arcytophyllum. Key results – Arcytophyllum leymebambense sp. nov. is morphologically distinct from its congeners by its acuminate leaf and sepal apices, hirsute-lanuginose seeds, and the presence of protective hooks surrounding the ovary. It inhabits humid, high-elevation grasslands known as “Jalca,” where it coexists with a diverse assemblage of montane species. The species appears to be endemic to the region and is currently known from only three populations. Its restricted distribution, combined with potential threats such as overgrazing and fire, supports a preliminary conservation assessment as Critically Endangered (CR). Conclusion – The discovery of Arcytophyllum leymebambense sp. nov. highlights the underestimated diversity of Andean Rubiaceae and provides evidence that Andean species form a grade within the diversification of Arcytophyllum. This pattern suggests a historical northward expansion of the lineage into the high mountains of Panama and Costa Rica.

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DOI: 10.5091/plecevo.157554

Authors: Marco M. Jiménez, Luis Baquero, Henry X. Garzón-Suárez, Carlos Martel, James A. Chamaya G., Nadia Lapo-González, Florian A. Werner, Gabriel A. Iturralde

Abstract: Background and aims – Telipogon is an orchid genus with a main diversity centre located in the tropical Andes. Some small-flowered Telipogon species, formerly classified under Stellilabium, remain poorly known. During recent fieldwork in southern Ecuador, an undetermined species of a miniature Telipogon was recorded and collected. We aimed to taxonomically identify the orchid and understand its phylogenetic relationships. Material and methods – We conducted field work in diverse parts of Ecuador and Peru, revised material deposited at various herbaria, and records available on iNaturalist. Furthermore, we extracted, amplified, and sequenced DNA sequences to evaluate the phylogenetic position of the undetermined species. Key results – The unidentified species turned out to be an undescribed Telipogon species, which we describe and name here as T. villonacoensis. It has also been recorded in Colombia and Peru, an unusually wide distribution for a Telipogon species. Telipogon villonacoensis is distinguished by its pale green to yellow flowers, the elliptic petals and lip, minute lobes and red coloration at its basal third. This species appears to have a patchy distribution and specialized habitat preferences, growing as an epiphyte in montane shrublands and forests. Although fewer than 200 individuals have been documented so far, and its habitats face ongoing threats, our conservation assessment indicates the species could be classified as not threatened. Phylogenetic analyses resulted in a well-resolved tree, in which T. villonacoensis is placed within the clade of the South American miniature Telipogon and sister to, but genetically distinct from, T. pogonostalix, though it is morphologically more similar to T. alexii, a species placed in another subclade of South American miniature Telipogon. Conclusion – Our results highlight the underestimated diversity and distribution range of miniature Telipogon and underscore the need for continued collaborative exploration and conservation in Andean ecosystems. These findings will contribute to a better understanding of orchid diversity and evolution of Telipogon species.

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