Habit: Mecardonia vandellioides grows as a procumbent herbaceous perennial spreading to 50 cm. The leaves are arranged oppositely, to 3 cm in length, oval to obovate, with an acute to obtuse leaf apex, and a serrate leaf margin.
The complete, perfect, zygomorphic flowers are solitary in leaf axils. The calyx has 5, fused into a tube, green, glandular pubescent, sepals. The corolla has 5, yellow with veins, fused into a bilabiate tube petals. The interior of the lobes are pubescent. There are 4 stamens fused to the corolla tube. The ovary is superior with 2 locules and numerous seeds. The fruit is a capsule.
Habitat: Mecardonia vandellioides grows in wet Human Altered areas (yards and gardens).
Distribution: Mecardonia vandellioides occurs in the northern pine islands of the Lucayan Archipelago as well as Mexico and the southern United States. It has spread throughout the Caribbean region.
Medicinal/Cultural/Economic usage: Mecardonia vandellioides is not known to be used medicinally in the Lucayan Archipelago.