Would it be possible for a shell to form around a foreign object?
A tree limb, Yes. A tree root, Absolutely. Nuts grow from the inside out. If I could have developed a tree to produce pecan bearing condoms, why wouldn't I make one which could produce those little bottles of Captain Morgans Spiced Rum? RW, WAIT! I'm not busting your chops, 'K? There's agriculture and there's fantasy.