Sometimes a plant becomes an obsession. That is the way I feel about Agave parryi.  It is definitely one of the few Agaves which always present a great show whenever they are encountered.  There are variations in the species exhibiting many forms.  I love them all.  I love the truncatas, the couesis, and even the distant cousin neomexicana.  In habitat they are even more attractive, and are definitely worth the sometimes perilous journey to observe. They are exceedingly tough plants which can handle unpredictable wintry conditions very well.  Therefore, if you are that way inclined. and would like to try your hand at growing, seeds are the easiest route to take.  Careful nurturing will ensure their survival.  And that way you can never have too much of them.