About.com: Trumpeting Trumpet Vines on the Landscape
   Information about trumpet vines and how to attract hummingbirds with flowing vines.
   http://landscaping.about.com/cs/groundcovervines/a/flowering_vines.htm

Eastcheam Ivy
   Contains information about different species of the plant along with photographs and resources.
   http://www.eastcheam.co.uk

Hoya
   Tips on culture, germination and care. Information on the species history, native habitat and systematics. Contains a larger photo gallery with photos of flowers, whole plant and leaves.
   http://www.hoyor.net/

Luffa.info
   Information and photopgaphs about luffa sponge gourds.
   http://www.luffa.info/

Passion Flowers
   Information about Passiflora collection with tips on growth and care in the UK climate.
   http://www.passionflow.co.uk

Poison Ivy, Oak & Sumac Information Center
   Pictures of various poisonous plants with pictures. Includes facts, remedies, treatment, question and answers, and FAQs.
   http://www.poisonivy.us/