seed-of-the-week

This plant grows only in the Southwest, so I’ll give you a few hints.

mystery-seed-36

When the seed is on the plant it is covered. I have opened the covering here.

mystery-seed-36-2

The seeds are large, about the size of an almond. They are not edible but the plant is useful and is sometimes grown as a crop.

Any guesses?

Edit:  The answer is now posted.