Re: Is it possible for a dill and parsley to cross- pollinate?

It is unlikely that dill (Anethum graveolens) and parsley (Petroselinum crispum 
var. crispum) hybridized because they are in different genera in the carrot 
family. Generally, species in different genera do not hybridize. 

You may simply have a weed that is neither parsley nor dill. Dill has yellow 
flowers. Parsley has greenish-yellow to reddish flowers. Perhaps your local 
cooperative extension agent could identify it for you. 

Another possibility is you have another variety of parsley. There are several 
botanical varieties of parsley, some with flat leaves, others with curled 
(crisped) leaves. Turnip-rooted parsley (Petroselinum crispum var. tuberosum) 
is grown for its fleshy roots, has flat leaves, and its leaves have no strong 
flavor.