Bo
- Boehmeria
- N Boehmeria cylindrica — false nettle, bog-hemp, smallspike false nettle
- Bolboschoenus
- N Bolboschoenus fluviatilis — river bulrush, river clubrush
- N Bolboschoenus maritimus — saltmarsh bulrush, bayonet grass, saltmarsh clubrush
- Borago
- X Borago officinalis — common borage, beeplant, beebread
- Botrychium
- N Botrychium acuminatum — pointed moonwort
- N Botrychium ascendens — upswept moonwort, triangle-lobed moonwort
- N Botrychium campestre — prairie moonwort, prairie dunewort
- N Botrychium dissectum — lacyleaf grapefern, cutleaf grapefern, cutleaf moonwort
- N Botrychium hesperium — western moonwort
- N Botrychium lanceolatum — lanceleaf grapefern, triangle moonwort
- N Botrychium lunaria — common moonwort, moonwort grapefern
- N Botrychium matricariifolium — daisyleaf moonwort, matricary grapefern, matricary moonwort, chamomile grapefern
- N Botrychium minganense — Mingan's moonwort
- N Botrychium multifidum — leathery grapefern
- N Botrychium oneidense — Lake Oneida grapefern, blunt-lobed grapefern
- N Botrychium pallidum — pale moonwort
- N Botrychium pseudopinnatum — false northwestern moonwort
- N Botrychium rugulosum — St. Lawrence grapefern, rugulose grapefern, ternate grapefern
- N Botrychium simplex — little grapefern, least moonwort
- N Botrychium spathulatum — spatulate moonwort, spoonleaf moonwort
- N Botrychium virginianum — rattlesnake fern
- Bouteloua
- N Bouteloua curtipendula — sideoats grama
Read more about this topic: List Of Canadian Plants By Genus B