Along the gravel road up to the convent a small tree with a dark, gnarly trunk was putting on a show with its two-inch wide, white, yellow-throated blossoms, seen below:
In some places this is called Anacahuite, and up north it's often labeled Texas Olive and marketed as a pretty tree able to survive in sunny, dry places. In fact, judging from nursery web pages, it's almost become a mainstay of hot-weather, xeric landscape gardening. The tree is CORDIA BOISSIERI of the Borage or Forget- me-not Family.
If you were with me in the Yucatan you might remember the red-flowered Ciricote so conspicuous in the dry- season scrub. Ciricote was Cordia sebestena, and Anacahuite is Cordia boissieri, so the two trees are very closely related.
On certain hot, dry, scrubby slopes in this area the white-blooming Anacahuites are so spectacular that you're put in mind of spring Dogwoods flowering up North -- despite the slopes' shimmering waves of heat and the air's dusty bite.