| Plantaginaceae | |
Mecardonia acuminata
| (Walter) Small | Fl. S.E. U.S. 1065, 1337 | 1903 |
| Plantaginaceae | |
Mecardonia berroi
| Marchesi | Comun. Mus. Nac. Hist. Nat. 4(60): 1–3 | 1975 |
| Plantaginaceae | |
Mecardonia caespitosa
| (Cham.) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98: 87 | 1946 |
| Plantaginaceae | |
Mecardonia dianthera
| (Sw.) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98(2): 87 | 1946 |
| Plantaginaceae | |
Mecardonia exilis
| (Brandegee) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98: 87 | 1946 |
| Plantaginaceae | |
Mecardonia flagellaris
| (Cham. & Schltdl.) Rossow | Candollea 42(2): 448 | 1987 |
| Plantaginaceae | |
Mecardonia grandiflora
| (Benth.) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98: 87 | 1946 |
| Plantaginaceae | |
Mecardonia herniarioides
| (Cham.) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98(2): 87 | 1946 |
| Plantaginaceae | |
Mecardonia kamogawae
| Greppi & J.C. Hagiw. | Darwiniana 49(1): 43–46, f. 1–2, map | 2011 |
| Plantaginaceae | |
Mecardonia montevidensis
| (Spreng.) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98(2): 87 | 1946 |
| Plantaginaceae | |
Mecardonia ovata
| Ruiz & Pav. | Fl. Peruv. Prodr. 95 | 1794 |
| Plantaginaceae | |
Mecardonia peduncularis
| (Benth.) Small | Fl. S.E. U.S. 1338 | 1903 |
| Plantaginaceae | |
Mecardonia procumbens
| (Mill.) Small | Fl. S.E. U.S. 1065, 1338 | 1903 |
| Plantaginaceae | |
Mecardonia pubescens
| Rossow | Candollea 42(2): 463–465, f. 10 | 1987 |
| Plantaginaceae | |
Mecardonia pusilla
| Mart. | Nov. Gen. Sp. Pl. 3(1): 16, t. 28 | 1829 |
| Plantaginaceae | |
Mecardonia radicata
| (Benth.) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98: 87 | 1946 |
| Plantaginaceae | |
Mecardonia reneeae
| Greppi & M.M. Sosa | Phytotaxa 303(3): 265, f. 1–2; tab. 1 | 2017 |
| Plantaginaceae | |
Mecardonia serpylloides
| (Cham. & Schltdl.) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98: 87 | 1946 |
| Plantaginaceae | |
Mecardonia tenella
| (Cham. & Schltdl.) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98: 87 | 1946 |
| Plantaginaceae | |
Mecardonia tenuis
| Small | Fl. S.E. U.S. 1065, 1338 | 1903 |
| Plantaginaceae | |
Mecardonia vandellioides
| (Kunth) Pennell | Proc. Acad. Nat. Sci. Philadelphia 98(2): 87 | 1946 |
| Plantaginaceae | |
Mecardonia viridis
| Small | Fl. S.E. U.S. 1065, 1338 | 1903 |