A new dimeric open-chain monoterpene glucoside, 5''-hydroxydigipenstroside {1-beta- D-glucopyranosyl)-8-[5'',8''-dihydroxy-2'',6''-dimethyl-2''( E),6''( E)-octadienoyl]-5,8-dihydroxy-2,6-dimethyl-2( E),6( E)-octadienoate} has been isolated from leaves of PENSTEMON DIGITALIS Nutt. In addition, the novel trimeric open-chain monoterpene glucoside penstriatoside {1-(beta- D-glucopyranosyl)-8-[5'',8''-dihydroxy-2'',6''-dimethyl-2''( E),6''( E)-octadienoyl-8''-(5''',8'''-dihydroxy-2''',6'''-dimethyl-2''' ( E)6'''( E)-octadienoyl)]-5,8-dihydroxy-2,6-dimethyl-2 ( E),6( E)-octadienoate} has been encountered. The structures of both compounds have been elucidated by spectroscopic means (FD-, FAB-mass, (1)H-, (13)C-NMR, COSY, DEPT).