Cassia Buttercream is a large shrub or small tree that gets 8-10' tall and wide. It's from South America and only grows in zones 8-10. Cassia or Senna. They changed the name a few years ago.
I bought this plant as a tiny 4" pot at The Huntington plant sale a few years ago. I potted it up a few times as it grew and then planted it in the ground. Our backyard bakes so much that I wanted some substance back there around my vegetable raised beds. I didn't know that it would get so wide. It's my own fault for planting it where I did at the end of one of the beds. It's so wide now that I can barely get around it. I even cut it back a few months ago.
In the summer daytime I noticed ants hanging around on the leaves. Usually ants are a sign of another insect because ants cultivate aphids and other sucking insects that secrete sugars. But I didn't see any other bugs. Research says that some Cassias have extrafloral nectaries which attract ants probably to deter herbivores.
It is a beautiful plant flowering in autumn. But after it's done blooming, I'm going to cut it back and move it to a better spot. Wish me luck!
Happy Gardening!