The Genus Mecardonia
This is a medium-sized genus of herbaceous plants from North America and South America, including the Coastal Southeast. At least two species are native to the Coastal Southeast.
Plantaginaceae is a fairly large family that ranges throughout the world. It includes herbaceous annuals and perennials, and shrubs. Familiar garden genera include angelonia (Angelonia,) snap dragon (Anthirrhinum,) foxglove (Digitalis,) nemesia (Nemesia,) Brazilian snapdragon (Otacanthus,) firecracker plant (Russelia) and speedwell (Veronica.) Many of these plants were previously included in the family, Scrophulariaceae.
Most references indicate that this plant is a hybrid. It resembles a native wildflower of the Coastal Southeast, Mecardonia procumbens.
This is a low, spreading herbaceous plant that grows only a few inches tall. The stems root where they touch the ground and will trail over the edge of a pot. Leaves are small and bright green. The flowers are small but are bright yellow and produced abundantly throughout the growing season. Reportedly, it does not set seeds. Grow it in a reasonably moist, well-drained soil in full sun to part sun. It is reported to be cold hardy to 20 degrees F, making it a perennial in zone 9a and a heat-tolerant summer annual in the cooler parts of the Coastal Southeast.
This plant is available in local nurseries. Plants are propagated by division or cuttings.
I have grown this plant in a container of potting soil for a few years, so far. It grows and flowers profusely during the warm months. Its growth slows but continues through the winter. My plant is evergreen. Large sections of foliage have died when winter temperatures drop into the low 20’s F. It begins growing and flowering again in early March and recovers quickly.