Dryopteris crassirhizoma (Thick-Stemmed Wood Fern)

Dryopteris crassirhizoma, commonly known as thick-stemmed wood fern, is a perennial fern native to northeastern Asia. The rhizome has a history of traditional medicinal use and contains phloroglucinol derivatives and other bioactive compounds.

Historically, extracts from Dryopteris species were used as anthelmintics, but these preparations can have a narrow safety margin and adverse effects have been reported with excessive exposure in animals and people. For this reason, Dryopteris crassirhizoma should not be viewed as a routine nutritional ingredient for horses. Equine-specific safety and efficacy data are limited, and any use should depend on accurate species identification, controlled processing, conservative formulation, and appropriate professional oversight.