Agave nickelsiae is the new...I mean old name for Agave ferdinandi-regis (yes, ferdinandi is spelled correctly). Agave nickelsiae is often lumped by herbarium taxonomists (people who study dead plants) with Agave victoriae-reginae, but Agave nickelsiae can be easily distinguished by more glaucous foliage, larger leaves, and larger terminal black spines. Each tight, slow-growing clump will reach 10" tall x 18" wide. We'll let the taxonomists fight the name battle while we enjoy the plants in our garden. Under favorable cultivation conditions, Agave nickelsiae should flower in 12-15 years with a solitary, upright, 12' stalk of hummingbird-attracting flowers.