Ranunculus harveyi (Harvey's buttercup)

Bromopsis erecta
Bromus arvensis (field brome)
Bromus catharticus (rescuegrass)
Bromus ciliatus (fringed brome)
Bromus erectus
Bromus hordeaceus
Bromus kalmii (arctic brome)
Bromus mollis
Bromus racemosus (bald brome)
Bromus secalinus (rye brome)
Bromus squarrosus (corn brome)
Bromus sterilis
Brunei
Brunnera macrophylla
Brunnichia ovata (American buckwheat vine)
Bryonia dioica
Buglossoides purpurocaerulea
Bulbostylis capillaris ssp. capillaris (densetuft hairsedge)
Bulgaria
Bunias orientalis
Buphthalmum salicifolium
Bupleurum falcatum
Bupleurum rotundifolium (hare's ear)
Burkina Faso
Burma
Burmannia biflora (northern bluethread)
Burundi
Buxus sempervirens
Cakile edentula (American searocket)