plant What are the differences between *Persicaria filiformis*, *Persicaria thunbergii*, and *Persicaria filiformis*? An explanation of how to distinguish between similar species.
*Persicaria filiformis*, *Persicaria thunbergii*, and *Persicaria filiformis* are all perennial herbs belonging to the genus *Persicaria* in the rose family, and in Japan they grow in forest edges and other similar areas. Their most distinctive features are the hook-shaped thorns beneath the calyx and their fruits, which are burrs that stick to surfaces. These two species, as their names suggest, differ primarily in their overall size...
