Vascular plant diversity of the valley Antinaco-Los Colorados, La Rioja Argentina

Abstract

Vascular plant diversity of the valley Antinaco-Los Colorados, La Rioja Argentina. The Antinaco-Los Colorados Valley is an extensive plain of the Monte ecoregion in the center-west of La Rioja (Argentina). This study provides a comprehensive inventory of the diversity of vascular plants growing spontaneously in the valley. A total of 264 species distributed in 57 families and 181 genera were recorded in four types of vegetation during 90 field trips. Eighteen species are new records for the province. The most diverse families were Asteraceae (35 spp., 13%), Poaceae (32 spp., 12%), Fabaceae (19 spp., 7%), Solanaceae (19 spp., 7%) and Cactaceae (16 spp., 6%). The best represented genera were Tillandsia (10 spp.), Solanum (6 spp.), Atriplex (5 spp.), Lycium (5 spp.) and Prosopis (5 spp.). The 13% of species (35) are introduced, mostly belong to families Poaceae (8 spp.), Asteraceae (5 spp.), Brassicaceae (5 spp.) and Chenopodiaceae (5 spp.). The valley includes 84 endemisms of level National, Regional and Provincial, 41% of which belongs to the family Cactaceae (13 spp.), Asteraceae (9 spp.), Solanaceae (7 spp.), Chenopodiaceae (6 spp.) and Euphorbiaceae (6 spp.). The dominant forms of life were the Phanerophytes (28%), Therophytes (28%) and Hemicryptophytes (21%). The valley concentrates approximately 17% of the diversity of vascular plants known for La Rioja.