You can access a list of some of the Poisonous and Dangerous species in your area by visiting our online guide at: Poisonous and Dangerous Species Guide. Just type in your zip code and click "go". Each plant listing includes a thorough description, plant height, habitat preference, etc.
You may also study the Poisonous Plants of the Southern United States list. Don't forget checking with local experts such as your County Cooperative Extension Horticulture Agent, or members of the Virginia Native Plant Society. Of course, a good nursery with knowledgeable help should provide excellent information as well. Good luck!