AND SHRUBS. 153 



etc., may be determined from the systematic list which makes up 

 the closing part of this paper. 



TREES AND SHRUBS. 



1. Species belonging to bogs and wet places.— The species are 

 shrubs, the last two, only, becoming small trees. They are : the 

 meadow-sweet (Spiraea), red-osier dogwood (Cornus stoloni- 

 fera), button-bush (Cephalanthus), shiny willow (Salix lucida) 

 and pussy willow (S. discolor). 



2. Species of the low alluvial bottoms. — The shrubs are: 

 the false indigo (Amorpha fruticosa), sandbar willow (Salix 

 interior) and heart-leaved willow (S. cordata), the willows some- 

 times becoming small trees. The soft maple (Acer saccharinum) , 

 red birch (Betula nigra), almond-leaved willow (Salix 

 amygdaloides) and black willow (S. nigra) are trees. 



3. Species of higher rich alluvial bottoms. — The wild grape 

 (Vitis vulpina) and poison ivy (Rhus radicans) are woody vines, 

 the latter sometimes a low shrub; the elder (Sambucus can- 

 adensis), flowering currant (Ribes floridum) and the wahoo 

 (Euonymus) are shrubs, the last sometimes a small tree; all the 

 species of haws (Crataegus) and the sheep-berry (Viburnum 

 lentago) are small trees, the latter sometimes a shrub; and the 

 following species are trees: the box-elder (Acer negundo), hack- 

 berry ( Celtis), the ashes (Fraxinus, except F. pennsylvanica), 

 honey locust (Gleditsia), the butternut and walnut (Juglans), 

 cottonwood (Populus deltoid es) and white elm (Ulmus 

 americana) . 



4. Species of upland thickets. — The Missouri gooseberry 

 (Ribes missouriensis) and the hazel (Corylus americanus) are 

 shrubs, and the haws (Crataegus) and wild crab (Mains) are 

 small trees. 



5. Species of wooded rocky banks and open slopes. — The fol- 

 lowing are woody vines: the purple virgin 's-bower (Atragene), 

 climbing bittersweet (Celastrus) and the two honeysuckles 

 (Lonicera). The shrubs are: the American yew (Taxus), shad- 

 bush (Amelanchier botryapium), the dogwoods (Cornus alterni- 

 folia, amomum, aspcrifolia and circinata), shrubby cinquefoil 

 (Dasiphora), dwarf cherry (Prunus pumila), leather-wood 

 (Dirca), prairie nine-bark (Opulaster), wild gooseberry (Ribes 



