  | 
         plants with tuberous roots; NOT [plants
        with a taproot]  | 
        | 
         plants generally more than 5 dm tall  | 
        | 
         stem not purple-blotched  | 
        | 
         NOT [plants with a bluish tinge; flowers
        in dense globose heads; bracts spiny]  | 
        | 
         NOT [foliage spiny]  | 
        | 
         NOT [leaves usually trifoliolate,
        leaflets palmate, 10-30 cm wide]  | 
        | 
         NOT [leaves palmate with 5-7 large
        leaflets]  | 
        | 
         leaves 1-3 times pinnate or
        pinnate-ternate  | 
        | 
         leaves often with 5 or more primary
        segments and many leaflets  | 
        | 
         leaves divided into leaflets of unequal
        size; NOT [leaves divided into leaflets of about equal size]  | 
        | 
         leaflets finely to deeply serrate; NOT
        [leaflets entire or with a few lobes]  | 
        | 
         the central  flower pedicellate; NOT
        [the central flower in the umbellets sessile]  | 
        | 
         flowers white; NOT [flowers yellow]  | 
        | 
         fruit not spiny; NOT [fruit covered with
        short, hooked spines]  | 
        | 
         fruit less than 1 cm long; NOT [fruit
        more than 1 cm long]  | 
        | 
         fruit about as long as broad or slightly
        longer; NOT [fruit twice as long as broad or longer]  | 
        | 
         fruit oblong to elliptical; NOT [fruit
        linear to clavate]  | 
        | 
         fruit flattened but wingless; NOT [fruit
        strongly flattened, broadly winged]  | 
        | 
         fruits flattened laterally (parallel to
        the styles); NOT [fruits flattened dorsally (at right angles to the
        styles)]  | 
        | 
         fruit glabrous; NOT [fruit usually
        pubescent]  |