most probably a fero. could be a cross though. seeing the flower will be the corker for a correct id.
Probably a subspecies of Ferocactus gracilis http://www.cactus-art.biz/schede/FE...is/Ferocactus_gracilis/Ferocatus_gracilis.htm
Thank you everyone who responded! And thanks for the link, L. Plant! I will try to get a photo of it with flowers.
Thanks for everyone's input. I won't need to get a photo with the flowers, since I have definitely identified it as Ferocactus gracilis, common name Fire Barrel Cactus. Thank you, L. Plant, for pointing me to Ferocactus gracilis!
Ha! You made me laugh, Joclyn! Thanks for your input on this. I would like to see it in bloom too, but it is too late now. Sorry! It is a gorgeous cactus, isn't it? It's in a neighbor's yard; I'll try to catch the flowers next year.