The genus Astragalus (Leguminosae: Papilionoideae: Galegeae) in Mexico Author Castillón, Eduardo Estrada 0000-0003-1061-9862 Universidad Autónoma de Nuevo León, Facultad de Ciencias Forestales, A. P. 41, 67700, Linares, Nuevo León, Mexico aeduardoestradac@prodigy.net.mx Author Quintanilla, José Ángel Villarreal 0000-0001-9672-8693 Universidad Autónoma Agraria Antonio Narro, Departamento de Botánica, Saltillo, Coahuila, Mexico javillarreal00@yahoo.com Author Delgado-Salinas, Alfonso 0000-0002-9322-9968 Universidad Nacional Autónoma de México, Instituto de Biología, 21068 adelgado@ib.unam.mx Author Rebman, Jon P. 0000-0002-4150-7356 San Diego Natural History Museum, P. O. Box 121390, San Diego, California, 92112 jrebman@sdnhm.org text Phytotaxa 2023 2023-03-07 586 1 1921 1935 http://dx.doi.org/10.11646/phytotaxa.586.1.1 journal article 10.11646/phytotaxa.586.1.1 1179-3163 7703999 62.3. Astragalus nuttallianus DC. var. imperfectus (Rydb.) Barneby, Leafl. West. Bot. 3: 1009. 1942 Type:— USA , Nevada , Nye County , Rhyolite , 17 May 1909 , Heller 9637 ( holotype (based on Hamosa imperfecta ) NY00011921 !; isotype : RENO009575 digital image!, PH00013580 digital image!) . Hamosa imperfecta Rydb., Bull. Torrey Bot. Club 54: 329. 1927 . Leaflets elliptic, none retuse; calyx teeth short, 1–2 mm long; the tube 1.9–2.8 mm long, the trichomes appressed o slightly ascendant, up to 0.8 mm long. Distribution:— Northwestern Mexico, Baja California in northeastern (Cucupa Mts.), at El Mármol, 12 km N to Santa Ynés Ranch ( 29°53’N114°51’W ); in Sonora, isolated at the northwestern, adjacent to the Pinacate Volcano ( 31°46’N113°26’W ) and isolated also in San Carlos Bay ( 27°58’N111° 04’W ). Also, in Colorado , Utah , California , and Arizona ( USA ) ( Fig. 19 ). Habitat:— Adjacent to coastal dunes; gravel soils; bottom of canyons; stony plains; alluvial plains; desert scrubland; 1–420 m . Specimens examined:— BAJA CALIFORNIA : 18 April 1905 , Crater, Arrobrito, Cucapa Mts., D. MacDougal 203 ( NY ) , 24 February1973 , Agua Dulce, R. Moran 20260, J. L. Reveal ( NY ) ; SONORA : 15 April 1992 , Campo Rojo, east side of Pinacate volcanic field, R. S. Felger 92-481B, S. W. Whitely ( MEXU , NY ) ; 15 May 2010 , Ánimas Valley , 58.7 km (byr air) E. of Agua Prieta, Cuenca Los Ojos Foundation property, T. R. Van Devender 2010-406, A. L. Reina , C. Roll ( MEXU , USON ) ; 23 March 1970 , Mpio. Puerto Peñasco , ca. 0.5 km S of Pinacate Peak , Sierra Pinacate , R. S. Felger 19310 ( USON 15 April 1992 , Campo Rojo , east side of Pinacate volcanic field, R. S. Felger 92-481B. S. W. Whitely ( MEXU ).