Abbott - 26247 - United States
Álvarez M. - 15682 - Mexico
Arsène - 3515 - Mexico
Bush - 107 - United States
Bush - 836 - United States
Camp - 2570 - Mexico
Clemens - 369 - United States
Cross - s.n. - United States
Davidse - 39960 - United States
Dunn - 22962 - Guatemala
Eggert - s.n. - United States
Emig - 675 - United States
Engelmann - 21 - United States
Engelmann - 32829 - United States
Equisetum hyemale var. affine
Flores - JF-00289 - El Salvador
Gallegos - 7 - Mexico
Garcia - 378 - Mexico
García-Mendoza - 681 - Mexico
Gentry - 2108 - Mexico
Gentry - 4412 - Mexico
Gómez Chagala - 541 - Mexico
Gregg - s.n. - Mexico
Ledesma Corral - 2035 - Mexico
Lyonnet - 764 - Mexico
Mackensen - 3 - United States
Martin - 259 - Mexico
Martínez Meléndez - 1020 - Mexico
Matuda - 28146 - Mexico
Nee - 43893 - United States
Normand - s.n. - United States
Orcutt - 4273 - Mexico
Palmer - 10927 - United States
Palmer - 11851 - United States
Palmer - 11940 - United States
Palmer - 14186 - United States
Palmer - 5011 - United States
Palmer - 6477 - United States
Palmer - 9606 - United States
Pringle - 3329 - Mexico
Reverchon - 3379 - United States
Stevens - 1934 - United States
Timme - 15701 - United States
Wagenbreth - 885 - Mexico
Wilkinson - 131 - United States
Yatskievych - 11-48 - Mexico
Yatskievych - 90-07 - United States