Agave shrevei subsp. magna Gentry Agave shrevei subsp. magna Gentry, Agaves Cont. N. Amer.: 451-453, f. 16.1, 16.4, 16.5, 16.30-16.32, t. 16.1 y 16.3. 1982 sec. Espejo-Serna & López-Ferrari 2008