About half of agave species are polyploidal--they have more than 2 copies of each chromosome. So they self-pollinate perfectly well for many generations. Many plants in my garden have been isolated for 5 to 20 generations and are still going strong--but are starting to change.

Research indicates that this species varies, but generally has anywhere from 2 to 6 copies.

Even diploids in plants tend to self-fertilize fairly well, although they do require mixing with other plants every few generations. With generations 80 years long, this one's grand-daughters might need to meet other agave in 160 years or so...