Napoleon's plume

Not actually an orchid, but a tree in the legume family (Fabaceae). They're called orchid trees due to the similarity of the flowers. It's a perennial native to Burma. It has been naturalized in Texas and Florida, and the species name "monandra" (mono=one, andra=andros=man's house) refers to the fact that only one stamen produces pollen, distinguishing this species from other in its genus.