3-B:
Interestingly, "edda" in the sense of a tuberous root seems to me to be a misprint for "eddo"! All the Web pages I could find that use the word "edda" in relation to tuberous roots seem to be derived from one source: The Princeton WordNet. As far as I can see, no other dictionary gives "edda" this meaning, although many of them have "eddo" with that meaning. The WordNet also has "eddo".
Is "edda" an alternative version of "eddo"? Perhaps, but it's intriguing that I couldn't find any confirmation from an independent source. I've actually written to WordNet asking them if they could possibly have made a slip. I don't know whether I'll get a reply, but anyhow, I'd prefer to leave "edda" in the pending file for now, unless you have any additional information.
Both "eddo" and its plural "eddoes" are already Chihuahua words.
As for "argel", there the situation seems a little clearer. I couldn't actually see a dictionary entry for it anywhere, but there are Web pages that demonstrate the word is used for a medicinal plant indigenous to Africa, so I'll go along with that suggestion.