Key to Agave species of the Agave sect. Choritepalae: 1. Leaves without teeth or terminal spines, filaments> 50 mm ........................................................................................................... 5 1. Leaves with teeth and terminal spines; filaments <50 mm long ...................................................................................................... 2 2. Leaves 100–125 × 36–42 cm; Michoacán .................................................. A. infiernilloensis Etter, Kristen, Rosales & A.Vázquez 2. Leaves 30–60 × 14–26 cm ................................................................................................................................................................ 3 3. Robust purple inflorescence, rachis with dense purple bracts; Querétaro and San Luis Potosí .......................................................... .......................................................................................................................................... A. muxii Zamudio & G. Aguilar-Gutiérrez 3. Slime yellow inflorescence, rachis with green bracts ...................................................................................................................... 4 4. Rosettes with 20–40 leaves, which are broadly ovate to semi orbiculate, glaucous to glaucous-yellowish, 1.8–2.5 times longer than wide; spine 2.5–5 cm; Tlaxiaco, Oaxaca ........................................................................ A. gypsicola García-Mend. & D. Sandoval 4. Rosettes with 9–16 leaves, which are broadly lanceolate, occasionally ovate, glaucous, with transversal stripes, 2.5–5.0 times longer than wide; spine 0.6–0.8(–1.5) cm; Tehuantepec, Oaxaca ..................................................................... A. guiengola Gentry 5. Rosettes with epigeous offsets; leaves narrow (3–4 cm), widest at the base; flowers white to pale yellowish; mainly Sierra Madre Oriental, Coahuila and Nuevo León .......................................................................................... A. bracteosa S. Watson ex Engelm. 5. Rosettes with hypogeous offsets; leaves broad (15–20 cm), widest in the middle; flowers greenish yellow; Sierra Mazateca, Oaxaca and Sierra Zongolica, Veracruz ..................................................................................................... A. ellemeetiana K. Koch

Published as part of Etter, Julia, Kristen, Martin, Rosales-Martínez, C. Santiago & Vázquezgarcía, J. Antonio, 2022, Agave infiernilloensis (sect. Choritepalae, Asparagaceae), a gigantic new species from the Balsas Basin in Western Mexico, pp. 208-220 in Phytotaxa 564 (2) on pages 216-217, DOI: 10.11646/phytotaxa.564.2.4, http://zenodo.org/record/7087164