Royal Botanic Gardens Kew (UK) http://www.kew.org/

Royal Botanic Garden Edinburgh (UK) http://www.rbge.org.uk/

University of Oxford Botanic Garden (UK) http://www.botanic-garden.ox.ac.uk/

Cambridge University Botanic Garden (UK) http://www.botanic.cam.ac.uk/Botanic/Home.aspx

National Botanic Garden of Wales (UK) http://www.gardenofwales.org.uk/

The New York Botanical Garden (USA) http://www.nybg.org/

The Huntington Botanical Gardens (USA)
http://www.huntington.org/huntingtonlibrary.aspx?id=210&linkidentifier=id&itemid=210

Missouri Botanical Garden (USA) http://www.missouribotanicalgarden.org/

Chicago Botanic Garden (USA) http://www.chicagobotanic.org/

Brooklyn Botanic Garden (USA) http://www.bbg.org/

San Diego Botanic Garden (USA) http://www.sdbgarden.org/

Desert Botanical Garden (USA) http://www.dbg.org/

Hawaii Tropical Botanical Garden (USA) http://www.htbg.com/

The United States National Arboretum (USA) http://www.usna.usda.gov/

Lady Bird Johnson Wildflower Center (USA) http://www.wildflower.org/

Royal Botanical Gardens (Canada) http://www.rbg.ca/

Montreal Botanical Garden (Canada) http://espacepourlavie.ca/en/botanical-garden

Vandusen Botanical Garden (Canada) http://vancouver.ca/vandusen/

Botanical Garden Berlin-Dahlem (Germany) http://bgbm3.bgbm.fu-berlin.de/default_e.htm

Palmengarten (Germany) http://www.palmengarten.de/#/en_GB/index/index

Parks & gardens and Environment Dept. of the city of Nantes (France)
http://www.seve.nantes.fr/traduction/Anglais/defaulta.htm

Leiden University Botanic Garden (Holland) http://www.hortus.leidenuniv.nl/

National Botanic Garden of Belgium (Belgium) http://www.br.fgov.be/

Royal Botanical Garden of Madrid (Spain) http://www.rjb.csic.es/

The Botanical garden of Barcelona (Spain) http://www.jardibotanic.bcn.cat/

Royal Botanic Gardens Melbourne (Australia) http://www.rbg.vic.gov.au/

Royal Botanic Garden Sydney & Domain Trust (Australia) http://www.rbg.vic.gov.au/australian-garden

The Christchurch Botanic Gardens (New Zealand)
http://www.ccc.govt.nz/cityleisure/parkswalkways/christchurchbotanicgardens/index.aspx

Beijing Botanical Garden (China) http://en.beijingbg.com/index.asp

Shanghai Botanical Garden (China) http://en.shbg.org/index.action

South China Botanical Garden (China) http://www.scib.ac.cn/

Singapore Botanic Gardens (Singapore) http://www.sbg.org.sg/

Indonesian Botanic Gardens (Indonesia) http://www.bogor.indo.net.id/kri/

Kirstenbosch National Botanical Garden (South Africa) http://www.sanbi.org/gardens/kirstenbosch