It's certainly a flax. You say 'down the road' as if this might be in a location where people have been active rather than a really wild place. Could it possibly be a stray plant of common flax, Linum usitatissimum, which is a crop grown in Texas according a quick Google. Just a thought.

It's a great habit shot, but something showing the leaves and flower up close would help. You can post big pictures on photobucket.com and link to them here.

It looks like a crucifer to me but really need a close up of the flowers. Check the link below. Here is a link that might be useful: Brassiaceae of the southwest

That certainly DOES look like it! Thank you! I'll have to check next year to see if the underside of the petals are green. The foliage is rather grass-like. They are very pretty but yes, not native, so odd. Don't know where they came from. :) The Internet says they are a bulb, too, so another oddity.