What is "mecardonia"

Mecardonia (Axilflower) is a genus of herbaceous plants in the family Plantaginaceae (Plantain family). 31 species have been described, of which 12 are accepted. Its distribution is predominantly in South America, and South East United States, including Florida and Alabama but may be found as far north as Virginia. (see map) Five species are found in Argentina and three in the US.