Document Type

Article

Publication Date

2024

DOI

10.14522/darwiniana.2024.122.1221

Publication Title

Darwiniana, Nueva Serie

Volume

12

Pages

204-219

Abstract

Simbaña, W.; A. Tye, T. J. Motley & U. Eliasson. 2024. Taxonomic status, distribution and conservation of the Critically Endangered plant Psychotria angustata (Rubiaceae), endemic to Floreana Island, Galapagos. Darwiniana, nueva serie 12(2): 204-219.

Two species of Psychotria have been recognised in the Galapagos Islands, both understorey shrubs endemic to the archipelago: P. rufipes Hook.f. occurs on seven islands, including Floreana, while P. angustata Andersson is endemic to Floreana. Since their mid-19th century discovery, the taxonomic and ecological status of these species has been uncertain. To clarify this, we examined historical specimens and numerous recent collections of both species, and surveyed their distribution on Floreana. Examination of the original description of P. angustata enables restriction of its type to the single specimen Andersson 195, which we designate the lectotype. We found differences in leaf venation, indumentum, shape and size, which confirm the existence of two clearly different forms that were originally referred to two species. Where these occur together no intermediate individuals were found. Differences also exist in the indumentum of twigs, inflorescences and flowers, but flower colour appears to be similar (white to cream) in the two taxa. These differences are of a degree commonly treated as infra-specific in other species of Psychotria. We conclude that the two taxa hitherto recognised as species are better regarded as varieties within P. rufipes and provide the consequent new combination Psychotria rufipes var. angustata W. Simbaña & Tye stat. nov. Both taxa are threatened by humid forest destruction and introduced animals and plants. Surveys confirm the global Red-List status of P. rufipes var. angustata as Critically Endangered. Population age structure indicates regeneration of both taxa since the recent eradication of feral ungulates from Floreana, but invasive plants still threaten them.

Comments

Alternate title: "Estado taxonómico, distribución y conservación de la planta en peligro crítico Psychotria angustata (Rubiaceae), endémica de la isla Floreana, Galápagos"

Timothy Motley passed away in 2013.

Rights

© 2012 The Authors.

As of 2012, this work is licensed under a Creative Commons Attribution-NonCommercial 2.5 (Argentina) (CC BY-NC 2.5 AR) License.

Original Publication Citation

Simbaña, W., Tye, A., Motley, T., & Eliasson, U. (2024). Taxonomic status, distribution and conservation of the critically endangered plant Psychotria angustata (Rubiaceae), endemic to Foreana Iland, Glapagos. Darwiniana, Nueva Serie, 12, 204-219. https://doi.org/10.14522/darwiniana.2024.122.1221

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