Native annuals are, overall, much less widely available commercially than native perennials, shrubs, trees, and vines, so it's not uncommon for nurseries focused on stocking native plants to not have much in the way of annual plant offerings. Since they're not yet widely grown, there also may be less propagation information for them (how long of a stratification period they may need, for instance, and planting depth), which can slow the process of nurseries adding them to their inventory (once they can even source seed) since they'd need to experiment with the best way of growing them so they have the fewest losses.

Partridge Pea (Chamaecrista fasciculata, specifically variety fasciculata) is native in Maryland and has been documented in nearly every county. It's possible some specimens found growing wild are actually "escaped" progeny from home gardens that seeded into natural areas, where their genetic origin is unknown (maybe they were sourced from a population outside of Maryland), but the species itself is locally native.

Miri

Thank You!

You're welcome!