Hi Lori, welcome to ATP. I don't know the name of those broms, as they were living in the tree there when we bought this house.
Btw, I honestly wouldn't recommend you grow broms right in the center of a tree like this. It can cause rot in the Y of the tree and weaken the structure. The broms will grow just as well out on a big branch, and not cause problems there. As I said above, I am thinning that clump, and eventually will remove it altogether.
Those broms do well on the ground in clumps, too. In fact they developed even more colors and yellow stripes on the leaves, and bloomed nicely after I transplanted the pups.
