Mexico, Sonora, Santa Cruz Municipio, Rancho Los Fresnos Grassland Preserve. "El potrero de la linea", adjacent to US-Mexico border fence, just W of only cement border marker in E half of preserve.
31.33316 -110.39082 +-5m. WGS82
1608 meters (5274ft)
Semi-arid grassland
Perennial subshrub with stout taproot. Flowers white.