224 



Trans. Acad. JSci. of St. Louis. 



INDEX TO GENERA. 



172, 181, 



Abies 37, 190 

 Abronla 63 

 Acacia 176 

 26-^ 



188, pi. 4, 6, 8, 9, 11 

 Acorus 73, 164-5 

 Actinella 59, 61 

 Actinomeris 69 

 Adiantites 163 

 Aegilops 217 

 Aesculus 68 

 Agrimonia 69 

 Agropyrum 66, 217 

 Agrostis 205, 207, 217 

 Ailanthus 177 

 Aira 208, 217 

 Alasmodonta 75 

 Alisma 59 

 Allium 64 

 Alnus 166 



Alopecurus 205, 207, 217 

 Amaranthus 62 

 Ambrosia 63-4, 66, 69 

 Amelanchier 176 

 Armnannia 59 



Ammophila 62, 205,^207, 217 

 Amnicola 93 

 Amorpha 63, 68 

 Amphiachyris 60-1 

 Amphicarpaea 68 

 Amygdalus 176 

 Ancylus 90 

 Andrena 46-7 

 Andromeda 171 

 Andropogon 63-4, 200 (203), 217 



(220) 

 Androsace 66 

 Anemone 65 

 Anodonta 75 

 Anodontopsis 76 

 Antennaria 69 

 Antholithes 177 

 Anthoranthum 205, 217 

 Apios 68 

 Aplexa 91 



Aplopappus 62, 64 



Apocynophyllum 170 



Aralia 171 



Arisaema 69 



Aristida 64, 205, 217-9, pi. 18 



Arrhenatherum 200, 208, 217, 219, 



pi. 17 

 Artemisia 62-4 

 Arundinaria 216-9, pi. 17 

 Arundo 209, 217 

 Asarum 69 

 Asclepias 62-5 

 Asclepiodora 65 

 Asimina 68 

 Asplenium 163, 177 

 Aster 60-1, 66, 69 

 Astragalus 60-1, 64-5 

 Atriplex 66 

 Avena 208, 217-8, 220, pi. 19 



Bacillus xx 



Banksites 169 



Baptisia 65 



Berula 59 



Betula 166 



Bidens 69 



Bombax 177 



Bouteloua 60, 64-5, 200, 208, 217, 



220, pi. 19 

 Brachypodium 200, 209, 212, 217 

 Bromus 200-1, 209, 212, 217, 21f, 



pi. 18 

 Buchloe 64-5 

 Bumelia 170 

 Bythinia92, pi. 10 



Cacalia 69 

 Caesalpinia (176-7) 

 Calamagrostis 205, 207, 217 

 Calathea xxiv 

 Callicoma (165) 

 Calliopsis 48 (49, 50) 

 Callirrhoe 65 

 Callitriche 58 

 Camassia 60-1 



