A few years ago I was browsing in a roadside nursery in Mexico (San Luis Potosi State). I took a picture of this plant, but have not been able to identify it since. I apologize for the lack of scale. I believe the flowers are about 15 mm in diameter. From the twisted flower buds and opposite leaves I would guess that it's in the dogbane family (Apocynaceae), but this may be a rash assumption. Does anyone recognize it?
Ah, yes, Daniel, you are spot on. Square stems, nervy leaves, flowers with 2 stamens and a bracteose inflorescence (the unopened inflorescence visible behind the open flowers). Must be an acanth. D'oh!
