Key to Anthurium of Mexico and Middle America
| 1 a. Leaves palmately lobed or divided; leaf segments more than three or if three, then divided to the base | KEY A |
| 1 b. Leaves simple, sometimes lobed. |
| 2 a. Leaf blades 3-lobed, the margins constricted near the base of the anterior lobe | KEY B | |
| . | 2 b. Leaf blades not 3-lobed |
| 3 a.Leaf blades cordate or subcordate at base |
| 4 a. Leaf blades with prominent posterior lobes, conspicuously black punctate below | KEY C | ||
| 4 b. Leaf blades with posterior lobes, not punctate below or not conspicuously so | KEY D |
| 3b. Leaf blades not cordate or subcordate at base. |
| 5a. Leaves punctate on one or both surfaces | KEY E | |||
| 5b. Leaves not punctate on either surface | KEY F |