The use of California Peony (Paeonia californica) for bruise prevention is rooted primarily in traditional herbal medicine rather than scientific validation. Native American groups in California, such as the Chumash, reportedly used the roots of this plant for a range of ailments, including as a topical application for bruises, sore muscles, and other minor injuries. This traditional use likely arose from the broader application of peony species in herbal medicine, where related species like Paeonia lactiflora and Paeonia officinalis have been used in Chinese and European herbal traditions, respectively.

However, there is very little published scientific research specifically on the efficacy of Paeonia californica for bruise prevention. Most available information comes from ethnobotanical records rather than clinical or pharmacological studies. While some peony species contain compounds such as paeoniflorin and other glycosides, which have demonstrated anti-inflammatory and circulatory effects in laboratory settings, these findings cannot be directly extrapolated to California Peony without dedicated research. Thus, the evidence for its use in bruise prevention is weak and primarily based on traditional knowledge rather than rigorous scientific study.

In summary, the use of California Peony for bruise prevention is supported by historical and traditional use, but lacks substantial scientific evidence or clinical validation.