Benson16488, coccineus gurneyi, USA, Texas, Marathon
Benson15538, dasyacanthus neomexicanus, USA, Arizona, Artesia
Benson16491, dasyacanthus neomexicanus, USA, Texas, Ft. Stockton
Benson16616, engelmannii acicularis, USA, Arizona
Benson14767, engelmannii armatus, USA, California, Victorville
Benson13637, engelmannii purpureus, USA, Utah, St. George
Benson16633, fasciculatus, USA, Arizona
Benson14621, fendleri boyce-thompsonii, USA, Arizona, Superior
Benson10720, nicholii, USA, Arizona, Silver Bell Mts.
Benson11113, pectinatus, USA, Arizona, Douglas
Benson16479, pectinatus, USA, Texas, Marathon
Benson16504, pectinatus dasyacanthus minor, USA, Texas, Big Bend Nat. Pk.
Benson16518, pectinatus wenigeri, USA, Texas, Sanderson
Benson16521, pectinatus wenigeri, USA, Texas, Langtry
Benson16550, reichenbachii albertii, USA, Texas, Alice
Benson14658, triglochidiatus melanacanthus, USA, New Mexico, Sta. Fe
Benson14694, triglochidiatus melanacanthus, USA, Arizona, Canyon de Chelly
Benson15067, triglochidiatus melanacanthus, USA, Nevada, Joshua Tree Nat. Mon.
Benson15068, triglochidiatus melanacanthus, USA, Nevada, Joshua Tree Nat. Mon.
Benson15069, triglochidiatus melanacanthus, USA, Nevada, Joshua Tree Nat. Mon.
Benson15663, triglochidiatus melanacanthus, USA, California, Cushenberry Canyon
Benson15698, triglochidiatus melanacanthus, USA, Utah, Wellington
Benson15700, triglochidiatus melanacanthus, USA, Utah, Sevier Lake
Benson16563, triglochidiatus melanacanthus, USA, Texas, Fredericksburg
Benson16609, triglochidiatus melanacanthus, USA, Nevada, Antelope Mts.
Benson16485, viridiflorus correllii, USA, Texas, Marathon