One plant really putting on a show at Cuatro Palos was a bush or small tree maybe ten feet tall, and you can see one of its 8-inch blossoms at at the right.
In that picture you may recognize the plant as Angel's Trumpet, for it's often planted ornamentally in the US South. The plant is DATURA ARBOREA, or BRUGMANSIA ARBOREA, depending on your expert, a member of the Nightshade Family (tomatoes, potatoes, tobacco). The species is originally from the Peruvian Andes but now is spread worldwide through the tropics and subtropics, thanks to its striking blossoms.
In fact, the species has had its genes juggled by so many gardeners and horticulturalists for so long that it's fractured into any number of varieties. The one in the photo is a double-flowered variant. You can see a second corolla or a kind of crown emerging from the center of the main flower. The wild form just has a simple tubular corolla.
Since one of the plant's genus names is Datura, and Datura is the Jimsonweed genus -- you may remember Carlos Castinada's Don Juan making his hallucinogenic potions with Datura -- you might guess that Angel's Trumpet has other than angelic properties. On the Internet I find one report of a German youth who under the influence of Angel Trumpet cut off his penis. Elsewhere I read about a poisoning of someone who simply touched an Angel's Trumpet leaf. People into tripping out shouldn't fool with the Daturas.