I went to YouTube and searched "3 different mangos grafted on one tree" and came up with https://www.youtube.com/watch?v=lI578OUHJqI I haven't watched it as I can't grow mangos in my area; if I grew one in a pot I'd have to bring it inside every winter (for about 5 months) and it wouldn't be happy.

Any Tillandsia that has pups/offsets might develop into a ball shape, so bergeri can do so. I mostly see ionanthas in ball shape though. I'm sure other Tillandsia fans will give you other suggestions based on their experience with Tillandsias that can form a ball shape.

That's it. When I typed two II's it didn't work.!..and Houz vid link also never works for me. I drag..and nothing.

He's in Hawaii so T.ionotha slow as molasses would be good enough. Mine is about three years old..4 plants. Not exactly a ball. A hemisphere-lol.

I don't think that ionantha "balls" look like balls until maybe they are composed of a dozen or so plants. I have a few that I have hung up (using aluminum or steel wire or plastic bread bag ties) just because the plant has no more base to sit on. If I don't separate out the pups, eventually such plants look more, um, expensive :)

I also have another one that is some form of Bergeri (small plants, almost star shaped), pupping off one plant and those pups having pups. I don't recall that it has ever flowered but it may not feel the need to yet.

Oh, just thinking, another good one to see about forming into a ball is a Soft Gray Stricta, a plant that really likes to bloom and pup. They are easy to grow, too, and single plants are about the size of a woman's hand.