Flora and History of the Tónichi Area on the Río Yaqui, Municipality of Soyopa, Sonora, Mexico

We report 431 taxa in 269 genera and 69 families for the Tónichi area. The most diverse families are Fabaceae (61 taxa); Poaceae (40 taxa); Asteraceae (36 taxa); Euphorbiaceae (27 species); Malvaceae (22 species); Convolvulaceae (20 species); Solanaceae (18 species); Boraginaceae (15 species); Apocynaceae and Cactaceae (11 species each); and Acanthaceae and Nyctaginaceae (10 species each). The most speciose genera are Euphorbia (15 species); Ipomoea (11 species); Boerhavia and Cyperus (7 species each); Cuscuta, Physalis, and Solanum (6 species each); and Bouteloua, Portulaca, and Senna (5 taxa each). There are 25 non- native species (5.8%) in the Tónichi flora.

Tónichi was the northernmost Pima Bajo Indian village upstream of Ónavas, Movas, and Nuri. A branch railroad connected Estación Corral near Ciudad Obregón to Tónichi from 1908 to 1945. The smelter at Toledo processed regional ores until 1911 when it was shut down by raiding Yaquis. During the Mexican Revolution in 1911, federal troops defeated Francisco I. Madero’s rebels in the Batalla de Tónichi at Loma Maderista near Toledo.