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Issue: Vol. 702 No. 1: 22 May 2025
Type: Article
Published: 2025-05-22
DOI: 10.11646/phytotaxa.702.1.6
Page range: 83-92
Abstract views: 179
PDF downloaded: 9

Rediscovery of Sicydium nereoi (Cucurbitaceae), a critically endangered micro-endemic of riverine islands in Esquina, northeastern Argentina, with details on morphology, ecology, and conservation

Instituto de Botánica del Nordeste (CONICET-UNNE), Sargento Cabral 2131, c.c. 209, C.P. 3400. Corrientes, Argentina; Facultad de Ciencias Exactas, Naturales y Agrimensura. UNNE. Avenida Libertad 5470, CP 3400. Corrientes, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
Instituto de Botánica del Nordeste (CONICET-UNNE), Sargento Cabral 2131, c.c. 209, C.P. 3400. Corrientes, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
Instituto de Botánica del Nordeste (CONICET-UNNE), Sargento Cabral 2131, c.c. 209, C.P. 3400. Corrientes, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
Instituto de Botánica Darwinion, Labardén 200, B1642HYD San Isidro, Buenos Aires, Argentina
conservation emended descriptions morphology Sicydium Eudicots

Abstract

This study provides a comprehensive morphological description and updated information of Sicydium nereoi, a microendemic climbing species of Cucurbitaceae, rediscovered in the riparian islands of Esquina, Corrientes, Argentina, after 50 years of being known only from the type specimen. We document for the first time the morphology of the pistillate flowers, fruits, and seeds, which differ from other Sicydium species by their ovoid, fleshy fruits, densely pubescent ovary, and glandular trichomes. A total of thirty-four individuals were recorded in three populations, restricted to an area of occupancy of 8 km² on organic-rich, calcareous soils. Based on IUCN criteria, we assign S. nereoi to the Critically Endangered (CR) category due to its limited distribution, small population size, and threats from habitat degradation and land use change. These findings provide key insights into the species’ morphological distinctiveness, ecological niche, and urgent conservation needs.

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How to Cite

Florentín, J.E., Medina, W.A., Delvescovo, N.S. & Pozner, R. (2025) Rediscovery of Sicydium nereoi (Cucurbitaceae), a critically endangered micro-endemic of riverine islands in Esquina, northeastern Argentina, with details on morphology, ecology, and conservation. Phytotaxa 702 (1): 83–92. https://doi.org/10.11646/phytotaxa.702.1.6