Aralia soratensis Marchal, a new tree and genus for Ecuador

Abstract

A new tree and genus of the family Araliaceae has been recorded for the first time in Ecuador. The discovery of several specimens took place in semi-deciduous piedmont forests of Catamayo–Alamor and in lower montane semi-deciduous forests of Catamayo–Alamor, in Loja Province, specifically in the cantons of Macará, Paltas, and Gonzanamá. The finding was made in the Laipuna Nature Reserve (property of Naturaleza y Cultura Internacional), located about 20 km from Macará, at an altitude of 1120 m a.s.l. During a botanical expedition in November 2009, a tree approximately 7 meters tall was collected, unknown to local inhabitants. After analysis in Ecuadorian herbaria (LOJA, QCNE, QCA) and consultation with national taxonomic specialists, it was confirmed to be Aralia soratensis Marchal, a species typically distributed in the central and Pacific regions of South America, especially in northern Argentina, southwestern Bolivia, and southern Peru. In the latter country, a collection was made in the northwest, within the Cerros de Amotape Protected Area, in the department of Tumbes. In Ecuador, besides the record in Laipuna Reserve in Macará canton, specimens have also been identified in other cantons of Loja Province, such as Gonzanamá (Sacapalca sector, 1350 m a.s.l.), and more frequently in Paltas, particularly in the lower part of Pisaca Hill (1857 m a.s.l.). Research and monitoring of the identified plants have determined that Aralia soratensis flowers between November and January, coinciding with the onset of the rainy season, and fruits between January and March. So far, two populations with few individuals have been identified in the cantons of Macará and Paltas, growing in humid sites or dry ravine beds, where it finds favorable niches for its development.