Is pedúnculo always stalk?

Question

I've seen in the "Word of the day" that pedúnculo is stalk, and I know this is true for plants. However, this word is also a part of some animals that permanently attach themselves to rocks (like certain barnacles), and whose "pedúnculo" can even contain the abdomen of the animal. Do you call this stalk as well'

Answer 1

I don't know about always, but in the case of barnacles, at least, the answer is yes. From Wikipedia:

Barnacles are encrusters, attaching themselves permanently to a hard substrate. The most common, "acorn barnacles" (Sessilia) are sessile, growing their shells directly onto the substrate. The order Pedunculata ("goose barnacles" and others) attach themselves by means of a stalk.

Answer 2

<http://dictionary.reference.com/search'q=stalk>

To answer your question you would need to look at the definition of stalk. Read the third definition of the word at this link.