| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| BEGL | Betula glandulosa Michx. | Betula nana | Betulaceae
|
| BEHO | Betula �hornei Butler (pro sp.) | | Betulaceae
|
| BEJA | Betula �jackii Schneid. | | Betulaceae
|
| BEKE2 | Betula kenaica W.H. Evans | Betula papyrifera var. kenaica | Betulaceae
|
| BELEU | Betula lenta L. var. uber Ashe | Betula uber | Betulaceae
|
| BELE | Betula lenta L. | sweet birch | Betulaceae
|
| BELUF | Betula lutea Michx. f. var. fallax Fassett | Betula alleghaniensis var. alleghaniensis | Betulaceae
|
| BELUM | Betula lutea Michx. f. var. macrolepis Fern. | Betula alleghaniensis var. macrolepis | Betulaceae
|
| BELU | Betula lutea Michx. f. | Betula alleghaniensis var. alleghaniensis | Betulaceae
|
| BEMAS | Betula mandshurica (Regel) Nakai var. szechuanica (Schneid.) Rehd. | Betula platyphylla var. szechuanica | Betulaceae
|
| BEMA2 | Betula mandshurica (Regel) Nakai | Betula platyphylla var. platyphylla | Betulaceae
|
| BEMI2 | Betula michauxii Sarg. | Betula nana | Betulaceae
|
| BEMI | Betula minor (Tuckerman) Fern. | dwarf white birch | Betulaceae
|
| BEMU2 | Betula murrayana Barnes & Dancik | Murray's birch | Betulaceae
|
| BENAE | Betula nana L. ssp. exilis (Sukatschev) Hult�n | Betula nana | Betulaceae
|
| BENAG | Betula nana L. var. glandulifera (Regel) Boivin | Betula pumila var. glandulifera | Betulaceae
|
| BENAR | Betula nana L. var. renifolia (Fern.) Boivin | Betula pumila var. renifolia | Betulaceae
|
| BENAS | Betula nana L. var. sibirica Ledeb. | Betula nana | Betulaceae
|
| BENA | Betula nana L. | dwarf birch | Betulaceae
|
| BENEK | Betula neoalaskana Sarg. var. kenaica (W.H. Evans) Boivin | Betula papyrifera var. kenaica | Betulaceae
|
| BENE4 | Betula neoalaskana Sarg. | resin birch | Betulaceae
|
| BENI | Betula nigra L. | river birch | Betulaceae
|
| BEOCF2 | Betula occidentalis Hook. var. fecunda Fern. | Betula utahensis | Betulaceae
|
| BEOCI | Betula occidentalis Hook. var. inopina (Jepson) C.L. Hitchc. | Betula occidentalis | Betulaceae
|
| BEOC2 | Betula occidentalis Hook. | water birch | Betulaceae
|
| BEPAH | Betula papyrifera Marsh. ssp. humilis (Regel) Hult�n | Betula neoalaskana | Betulaceae
|
| BEPAO | Betula papyrifera Marsh. ssp. occidentalis (Hook.) Hult�n | Betula occidentalis | Betulaceae
|
| BEPAC | Betula papyrifera Marsh. var. commutata (Regel) Fern. | western paper birch | Betulaceae
|
| BEPAC2 | Betula papyrifera Marsh. var. cordifolia (Regel) Fern. | mountain paper birch | Betulaceae
|
| BEPAE | Betula papyrifera Marsh. var. elobata (Fern.) Sarg. | Betula papyrifera var. papyrifera | Betulaceae
|
| BEPAH2 | Betula papyrifera Marsh. var. humilis (Regel) Fern. & Raup | Betula neoalaskana | Betulaceae
|
| BEPAK | Betula papyrifera Marsh. var. kenaica (W.H. Evans) A. Henry | Kenai birch | Betulaceae
|
| BEPAM2 | Betula papyrifera Marsh. var. macrostachya Fern. | Betula papyrifera var. papyrifera | Betulaceae
|
| BEPAM | Betula papyrifera Marsh. var. minor (Tuckerman) S. Wats. & Coult. | Betula minor | Betulaceae
|
| BEPAN | Betula papyrifera Marsh. var. neoalaskana (Sarg.) Raup | Betula neoalaskana | Betulaceae
|
| BEPAO2 | Betula papyrifera Marsh. var. occidentalis (Hook.) Sarg. | Betula occidentalis | Betulaceae
|
| BEPAP | Betula papyrifera Marsh. var. papyrifera | paper birch | Betulaceae
|
| BEPAP2 | Betula papyrifera Marsh. var. pensilis Fern. | Betula papyrifera var. papyrifera | Betulaceae
|
| BEPAS | Betula papyrifera Marsh. var. subcordata (Rydb.) Sarg. | Betula utahensis | Betulaceae
|
| BEPA | Betula papyrifera Marsh. | paper birch | Betulaceae
|
| BEPE3 | Betula pendula Roth | European white birch | Betulaceae
|
| BEPI3 | Betula piperi Britt. | Betula utahensis | Betulaceae
|
| BEPLP | Betula platyphylla Sukatschev var. platyphylla | Asian white birch | Betulaceae
|
| BEPLS | Betula platyphylla Sukatschev var. szechuanica Schneid. | Szechuan white birch | Betulaceae
|
| BEPL2 | Betula platyphylla Sukatschev | Asian white birch | Betulaceae
|
| BEPO | Betula populifolia Marsh. | gray birch | Betulaceae
|
| BEPUB | Betula pubescens Ehrh. ssp. borealis (Spach) A.& D. L�ve | Betula borealis | Betulaceae
|
| BEPU5 | Betula pubescens Ehrh. | downy birch | Betulaceae
|
| BEPUG2 | Betula pumila L. var. glabra Regel | bog birch | Betulaceae
|
| BEPUG | Betula pumila L. var. glandulifera Regel | bog birch | Betulaceae
|
| BEPUP2 | Betula pumila L. var. pumila | bog birch | Betulaceae
|
| BEPUR | Betula pumila L. var. renifolia Fern. | bog birch | Betulaceae
|
| BEPU4 | Betula pumila L. | bog birch | Betulaceae
|
| BEPU3 | Betula �purpusii Schneid. | | Betulaceae
|
| BERE3 | Betula resinifera Britt. | Betula neoalaskana | Betulaceae
|
| BESA | Betula �sandbergii Britt. | | Betulaceae
|
| BESA3 | Betula �sargentii Dugle | | Betulaceae
|
| BESA4 | Betula saxophila Lepage | Betula minor | Betulaceae
|
| BETE3 | Betula terrae-novae Fern. | Betula nana | Betulaceae
|
| BEUB | Betula uber (Ashe) Fern. | Virginia roundleaf birch | Betulaceae
|
| BEUN | Betula �ungavensis Lepage | Betula hornei | Betulaceae
|
| BEUT | Betula �utahensis Britt. (pro sp.) | | Betulaceae
|
| BEVE2 | Betula verrucosa Ehrh. | Betula pendula | Betulaceae
|
| BEWI2 | Betula �winteri Dugle | | Betulaceae
|
| BETUL | Betula L. | birch | Betulaceae
|
| BEMA | Betula-Alnus maritima Marsh. | Alnus maritima | Betulaceae
|
| BISE2 | Biancaea sepiaria (Roxb.) Todaro | Caesalpinia decapetala | Fabaceae
|
| BIAL3 | Biatora albohyalina (Nyl.) Bagl. & Carestia | | Bacidiaceae
|
| BIAN | Biatora anthracophila (Nyl.) Hafellner | | Bacidiaceae
|
| BIBO | Biatora botryosa Fr. | | Bacidiaceae
|
| BICA9 | Biatora carneoalbida (Mull. Arg.) Coppins | Mycobilimbia carneoalbida | Porpidiaceae
|
| BICH | Biatora chrysantha (Zahlbr.) Printzen | | Bacidiaceae
|
| BICU3 | Biatora cuprea (Sommerf.) Fr. | | Bacidiaceae
|
| BIEF | Biatora efflorescens (Hedl.) Rasanen | | Bacidiaceae
|
| BIEP | Biatora epixanthoides (Nyl.) Diederich | Mycobilimbia epixanthoides | Porpidiaceae
|
| BIFL2 | Biatora flavopunctata (Tonsberg) Hinteregger & Printzen | | Bacidiaceae
|
| BIHE5 | Biatora helvola (Korber) Hellbom | | Bacidiaceae
|
| BIME3 | Biatora meiocarpa (Nyl.) Arnold | | Bacidiaceae
|
| BIPO3 | Biatora porphyrospoda Anzi | | Bacidiaceae
|
| BIPU3 | Biatora pullata Norman | Lecidea amaurospoda | Lecideaceae
|
| BISP | Biatora sphaeroides (Dickson) Korber | Mycobilimbia sphaeroides | Porpidiaceae
|
| BISU | Biatora subduplex (Nyl.) Printzen | | Bacidiaceae
|
| BITU | Biatora turgidula (Fr.) Nyl. | | Bacidiaceae
|
| BIVA5 | Biatora vacciniicola (Tonsberg) Printzen | | Bacidiaceae
|
| BIVE60 | Biatora vernalis (L.) Fr. | | Bacidiaceae
|
| BIATO2 | Biatora Fr. | biatora | Bacidiaceae
|
| BIAL2 | Biatorella albidula (Willey) Zahlbr. | Myrionora albidula | Lecanoraceae
|
| BICA7 | Biatorella campestris (Fr.) Almq. | Sarcosagium campestre | Acarosporaceae
|
| BICL2 | Biatorella clauzadeana Llimona & Vezda | Acarospora clauzadeana | Acarosporaceae
|
| BICL | Biatorella clavus (DC.) Th. Fr. | Sarcogyne clavus | Acarosporaceae
|
| BICO8 | Biatorella conspersa (Fee) Vainio | Piccolia conspersa | Biatorellaceae
|
| BICY2 | Biatorella cyphalea (Tuck.) Zahlbr. | | Biatorellaceae
|
| BIFL | Biatorella floridensis H. Magn. | | Biatorellaceae
|
| BIFO2 | Biatorella fossarum (Dufour ex Fr.) Th. Fr. | Biatorella hemisphaerica | Biatorellaceae
|
| BIHE6 | Biatorella hemisphaerica Anzi | | Biatorellaceae
|
| BIHY2 | Biatorella hypophaea (Nyl.) Blomb. & Forss. | Sarcogyne privigna | Acarosporaceae
|
| BIKU | Biatorella kulshanensis Herre | Sarcogyne kuleshanensis | Acarosporaceae
|
| BIMI4 | Biatorella microhaema Norman in Th. Fr. | Strangospora microhaema | Acarosporaceae
|
| BIMO2 | Biatorella moriformis (Ach.) Th. Fr. | Strangospora moriformis | Acarosporaceae
|
| BIOC | Biatorella ochrophora (Nyl.) Arnold | Strangospora ochrophora | Acarosporaceae
|
| BIPL | Biatorella plicata H. Magn. | | Biatorellaceae
|