Two more agaves I would recommend for your collection are these two that are smaller and slower growers, which makes it nice for collectors like me who have to drag plants in for the winter.
Agave sharkskin, sometimes called sharkskin shoes, is a naturally-occurring hybrid of a. asperima and a. victoria regina, both Mexico natives. Or you may read that sharkskin is a hybrid of a. scabra and a. fernandii. Same plants by older and younger classifications; no matter. It has a thick skin with a rough feel, hence the name sharkskin. It has dark red tips and a dark blue, almost teal color. I have read descriptions that say it is olive green with a blue cast. Mine seems bluer. The leaves are thick, and when the rosette opens, outlines or designs of the center leaf are left on the surface of the newly unfurled one. Since it is native to Mexico, I don’t trust it to make it through our colder climate without freeze damage or death, so I do roll it inside for the winter. If you live farther south, it would probably do just fine outside in the ground. I have also shielded mine a bit from our full West Texas sun so that it doesn’t sunburn. With gradual exposure to early Spring sun, it would probably take full sun. I just didn’t do that this year.
Agave macrocantha, another Mexican native, has a very different look than most agaves and was new to me until I received this one as a gift from Mr. John Farmer of Kerrville. It was smaller then, of course, but has filled out nicely. This one is about four years old.
This agave has slender leaves that are long and round like a finger and form a nice tight rosette of leaves. It has a bright green color with a yellowish cast that is a little different to other agaves. I bring this one in for the winter, too.
I happen to think both of these specimens are worth the trouble of hauling them in and out by seasons. Perhaps you will as well.