FLOWERS: Calyx lobes acuminate; corolla tube 18-25 mm long, the throat 4-8 mm wide; anthers and stigma usually exserted. 2n=14. NOTES: See also parent taxon. Open sites, shrublands, pinyon-juniper woodland, coniferous forest; Apache, Coconino, Gila, Graham, Greenlee, Mohave, Navajo, Yavapai cos.; 1680-2840 m (5500-9300 ft); May-Sep; CA to CO, s to AZ and TX. Subsp. aggregata, with attenuate calyx lobes longer than the tube and anthers located in the throat, occurs from MT to s CO. Hybrids with I. tenuituba, intermediate in corolla size and color, are known from the Kaibab Plateau, San Francisco Peaks, and the White Mountains. REFERENCES: Dieter H. Wilken and J. Mark Porter, 2005, Vascular Plants of Arizona: Polemoniaceae. CANOTIA 1: 1-37.