Rhus copallina _Dwarf sumac_ 137 glabra _Smooth sumac_ 137 hirta, Sudw. _Staghorn sumac_ 134, 135 toxicodendron _Poison ivy_ 137 typhina, L. _Staghorn sumac_ 134, 135 venenata, DC. _Dogwood, Poison sumac_ 136, 137 vernix, L. _Dogwood, Poison sumac_ 136, 137 River ash (Fraxinus Pennsylvanica, Marsh.) 164, 165 birch (Betula nigra, L.) 65, 66 maple (Acer saccharinum, L.) 142-144 Robinia pseudacacia, L. _Locust_ 131, 132 viscosa, Vent. _Clammy locust_ 132 Rock chestnut oak (Quercus prinus, L.) 82-84 elm (Ulmus racemosa, Thomas) 99, 100 maple (Acer Saccharum, Marsh.) 144-146, 172 Rum cherry (Primus serotina, Ehrh.) 127, 128 S =Salicaceae.= (Willow family) 28-46 Populus alba, L. _Abele, White, Silver-leaf poplar_ 39, 40 balsamifera, L. _Poplar, Balsam. Balm of Gilead_ 36, 37 balsamifera, _var._ candicans, Gray. _Balm of Gilead_ 37-39, 171 balsamifera, _var._ intermedia _Poplar, Balsam_ 36 balsamifera, _var._ latifolia _Poplar, Balsam_ 36 candicans, Ait. _Balm of Gilead_ 37-39, 171 deltoides, Marsh. _Cottonwood, Poplar_ 34, 35 Populus grandidentata, Michx. _Poplar, Large-toothed aspen_ 31, 32 heterophylla, L. _Poplar, Swamp poplar, Cottonwood_ 33, 34 monilifera, Ait. _Cottonwood poplar_ 34, 35 tremuloides, Michx. _Poplar, Aspen_ 29, 30 Salix alba, L. _White willow_ 43, 45, 46 _var._ caerulea, Koch _White willow_ 45 _var._ vitellina, Koch _White willow_ 4 balsamifera, Barrett 171 discolor, Muhl. _Pussy willow, Glaucous willow_ 40, 41, 171 falcata, Pursh _Black willow_ 42 fragilis, L. _Crack willow, Brittle willow_ 43-45 nigra, Marsh. _Black willow_ 42, 43 Sassafras officinale, Nees _Sassafras_ 106-108 Sassafras, Karst. _Sassafras_ 106-108 Savin (Juniperus Virginiana, L.) 26-28 Scarlet oak (Quercus coccinea, Wang.) 88, 89 Scotch pine (Pinus sylvestris, L.) 11, 12 Scrub chestnut oak (Quercus prinoides, Willd.) 85 oak (Quercus ilicifolia, Wang.) 93, 94 pine (Pinus Banksiana, Lamb) 8,9 white oak (Quercus prinoides, Willd.) 85 Shadbush (Amelanchier Canadensis, Medic.) 116, 117 Shagbark (Carya alba, Nutt.) 49-51 Sheep berry (Viburnum Lentago, L.) 168, 169 Silver-leaf poplar (Populus alba, L.) 39, 40 maple (Acer saccharinum, L.) 142-144 =Simarubaceae.= (Ailanthus family) 133 Ailanthus glandulosus, Desf. _Tree of Heaven, Chinese sumac_ 133 Skunk spruce (Picea alba, Link) 16-18 Slippery elm (Ulmus fulva, Michx.) 97, 98 Small white birch (Betula populifolia, Marsh.) 66-68 Smooth sumac (Rhus glabra) 137 Soft maple (Acer rubrum, L.) 140-142 (Acer saccharinum, L.), 142-144 Sorbus Americana, Marsh. _Mountain ash_ 112, 113 sambucifolia, R[oe]m. _Mountain ash_ 113, 115 Sour gum (Nyssa sylvatica, Marsh.) 159, 160