Edit:Just looked it up, it means embarrased if it is followed by "grin" otherwise the explanations more towards shy are correct.
My favourite name together with foxglove (which in my language is closer to its latin name. Vingerhoedskruid, which means thimbleherb, but word for word, fingerhat (yes, that is what we call a thimble :P) herb. And it is digitalis in latin.
It is a wellknown poison so it is bound to have found it's way to literature and tv/movies.
Plus, it's a cool word ;)