Mexican Feather Grass
Mexican Feather Grass (Nassella tenuissima) is not known to be invasive in Maryland and there are no restrictions prohibiting Maryland nurseries from selling it.
We appreciate your concern about invasive plants. For future reference, here is our Maryland invasive plants list. https://extension.umd.edu/hgic/problems/invasive-plant-list.
In addition, the native plant page on our website includes several good resources for choosing native plants. There are some very nice ornamental grasses that are native to Maryland, such as little bluestem and switchgrass (among others). https://extension.umd.edu/hgic/native-plants