I was thinking this is a bougainvillea blossom, but it turns out it’s a set of bougainvillea bracts! The flowers of bougainvilleas are actually small and white while their bracts are colorful and bright. What are bracts? As this site here explains, they can take many forms and serve many purposes, but in general (it seems) they serve a flower (or florescence) in some way. Even the “petals” of a dogwood “flower” are actually bracts! This particular set of bracts had fallen this morning onto one of the (yellow-topped) tables outside the Huntington cafe.