About Dryopteris crassirhizoma Nakai
Dryopteris crassirhizoma is a fern species that belongs to the wood fern family Dryopteridaceae. It is a semi-evergreen fern that reaches 1 meter (3.3 feet) in both height and width. Narrowly divided fronds grow in a vase-like shape from a brown central crown. This species has been awarded the Royal Horticultural Society's Award of Garden Merit. Acylphloroglucinols known as flavaspidic acids, which are isolated from D. crassirhizoma, demonstrate in vitro antibacterial activity and inhibitory activity against fatty acid synthase. Two other constituents found in this fern, sutchuenoside A and kaempferitrin, have in vivo antiparasitic activity.