I noticed this photo on the database page for Caesalpinia gilleisii and I think it's actually C. pulcherrima . They are quite similar in growth pattern, leaves and seedpods, but the gilleisii have distinct red stamens, smooth petal edges, and a somewhat compact bud structure. The pulcherrima are uniformly yellow, ruffled, and the flower buds are held on long stalks. What do you think, tabbycat? Not much in our database for the solid yellow, so I pulled from the web, too. (For others looking at the photo, it's the yellow plant on the right, not the lily!)
Also this from Wikipedia:
https://en.wikipedia.org/wiki/...
From our database for C. :gilliesii: