Standard lists are available
Representative examples for higher plants include:
 * North America / US
 USDA Plants http://plants.usda.gov
 ITIS http://www.itis.usda.gov
NatureServe http://www.natureserve.org
* World
 IPNI International Plant Names Checklist
http://www.ipni.org/
 IOPI Global Plant Checklist
 http://www.bgbm.fu-berlin.de/IOPI/GPC/