Although transplanting wild plants is tempting and often successful, it is strongly discouraged, as yellow fritillary is quickly losing ground as a plentiful native plant. Many states have laws against harvesting native wild plants from public lands. Your best option is to find a native plant nursery that can send you either bulbs or container-grown plants. While there are many good reasons to want to plant native plants in a home garden (including attracting native pollinators and wildlife), in some cases it's difficult for these sometimes-delicate plants to make that transition. Generally, they're better left where they are.