British Clematis Society - http://www.britishclematis.org.uk/
Offers culture information, seed exchange, photographs, events, and featured plants. |
International Clematis Society - http://www.clematisinternational.com/
Provides cultivar registration, news, events and newsletter. |
The American Clematis Society - http://clematis.org/
Founded in 1996 for the purpose of encouraging and promoting the development and improvement of Clematis. Offers plant database, photographs, event schedule and basic culture information. |