Fronds of various ferns in the genus Notholaena produce an exudate which consists mostly of flavonoid aglycones. In some species we found small amounts of two dibenzoylmethanes or beta-diketones. These have been identified by spectroscopic methods. Both, 2',beta-4-trihydroxy-4',6'-dimethoxychalcone and 2',beta-dihydroxy-4',6',4-trimethoxychalcone, are novel natural products. The structures have been confirmed by synthesis of the latter compound.