on 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,