http://www.nps.gov/findapark/index.htm
http://www.edwardsaquifer.net/species.html
http://www.extremescience.com/earth.htm
http://www.outdoorresearchverticulture.com/2011/04/the-love-letter-wilderness-community/
http://www.globalchange.umich.edu/globalchange2/current/lectures/biodiversity/biodiversity.html
http://www.foragingtexas.com/
Here is an interesting one I found from the person who teaches the edible plants class at Houston Arboretum.