Canadian Wildlife Federation: http://cwf-fcf.org/en/resources/encyclopedias/native-plant-encyclopedia/
The US- Audubon https://www.audubon.org/native-plants
NWF: https://www.nwf.org/Garden-for-Wildlife/about/native-plants
Wildflowers (US) https://www.wildflower.org/
Canada: https://www.worldatlas.com/articles/native-plants-of-canada.html