| Baccharis |
albida, argentina, artemisioides, cabrerae, cordobensis, divaricata, famatinensis, gilliesii, kurtziana, melanopotamica, multiflosculosa, niederleinii, penningtonii, petrophila, phyteuma, polygama, retamoides, rodriguezii, rupestris, stenophylla, tenella, thymifolia, triangularis |
| Balbisia |
aphanifolia, calycina, miniata |
| Banara |
umbraticola |
| Barbaceniopsis |
humahuaquensis |
| Barneoudia |
balliana |
| Bartsia |
jujuyensis |
| Begonia |
hassleri, parodiana, sleumeri, tafiensis |
| Belloa |
santanica |
| Benthamiella |
azorella, azorelloides, chubutensis, graminifolia, lanata, longifolia, nordenskjoldii, patagonica, pycnophylloides, skottsbergii, sorianoi, spegazziniana |
| Berberis |
andeana, bidentata, comberi, copahuensis, grevilleana, hieronymi, jobii, jujuyensis, lilloana, ruscifolia |
| Bernardia |
argentinensis, asplundii, odonellii |
| Bipinnula |
polysyka |
| Blepharidachne |
benthamiana, hitchcockii |
| Boerhavia |
cordobensis, pulchella |
| Bolax |
gummifera |
| Bonamia |
sericea |
| Boopis |
anthemoides, castillonii, chubutensis, filifolia, necronensis, patagonica, pterocalyx, raffaellii |
| Borreria |
loretiana, nelidae |
| Bowlesia |
hieronymusii, ruizlealii, venturii |
| Brachyclados |
caespitosus, lycioides, megalanthus |
| Brachystele |
burkartii |
| Bredemeyera |
colletioides, microphylla |
| Bromus |
bonariensis, parodii, pellitus |
| Buddleja |
cordobensis |
| Bulbostylis |
guaglianoneae |
| Bulnesia |
schickendantzii |
| Burkartia |
lanigera |
| Butia |
noblickii |
