You could get away with it in a story that was really, really campy. Self-consciously so.
Otherwise, no.
Especially since a foxglove is whimsically named for its flower shape ... it's not a masculine image at all, not to get really literal about it but I assume you'll understand what I mean. And also since it is poisonous, it just sounds more like a stereotypical female villain name than a boy.
Maybe a really, really fey and vampy boy.
[/nonsensical ramblings]