Above you see a knee-high herb with 2-inch broad yellow flowers blossoming prettily along the hotel's sandy footpath. Marcia knows an old fellow in the vicinity who salvages every thrown-away or hurricane-uprooted plant he finds, and he had these growing all over his place. The plant is a member of the genus Turnera, probably TURNERA ULMIFOLIA. Three Turnera species are listed for this area so I can't be sure. Turneras are such unusual plants that they have their own family, the Turnera Family, or Turneraceae.
Turnera ulmifolia is a tropical plant with no generally accepted English name. The USDA refers to it as Ramgoat Dashalong, which is colorful enough. Yellow Alder seems to be its most frequent English name, though obviously it's no alder. Maybe the most apt English name I can find is Cuban Buttercup, though it's no Buttercup, either, and lives far beyond Cuba.
Many tropical cultures use Turnera ulmifolia medicinally. Its uses are so numerous and general that you wonder about them. It seems especially useful as an intestinal anti-inflammatory, and research shows that it shows high antioxidant activity.
A closely related and somewhat similar looking species, Turnera diffusa, often referred to as Damiana, also grows here. That species is internationally famed as an aphrodisiac. If you Google "Turnera" you'll get lots of pages selling that species as a "male enhancer."