Sphagnacee, 137. 
Sphagnum, 137, 170. 
Spice Bush, 93. 
Spiked Loosestrife, 55. 
Spikenard, 57. 
Spireea, 48. 
Spiranthes, 108. 
Splachnum, 170. 
Spongiocarpee, 160. 
Sporobolus, 123. 
Spotted Cowbane, 56. 
Spotted Wintergreen, 74. 
Spreading Dogbane, 87. 
Spring Beauty, 40. 
Spring Clotbur, 65. 
Spring Cress, 33. 
Spurge Family, 94. 
Spyridia, 161. 
Spyridiez, 161. 
Squamariee, 160. 
Squirrel-tail Grass, 128. 
Stachys, 83. 
Staff Tree Family, 43. 
Staghorn Sumach, 42. 
Star Cucumber, 55. 
Star-flower, 75. 
Star-flower (Houstonia), 60. 
Star Grass, 110. 
Statice, 75. 
Steironema, 76. 
Stellaria, 38. 
Stereocaulon, 153. 
Stipa, 124. . 
Stitchwort, 38. 
Stone-crop, 52. 
Stone-root, 82. 
Storksbill, 41. 
Stramonium, 86. 
Strawberry, 49. 
Strawberry Blite, 90. 
Strawberry Tomato, 85. 
_ Streptopus, 111. 
Stricta, 151. 
Striped Grass, 129. 
197 
Striped Maple, 43. 
Struthiopteris (Onoclea), 135. 
Sueda, 90. 
Sugar Maple, 43. 
Sumach, 42. 
Summary, 173. 
Summer Grape, 42. 
Sundew Family, 36. 
Sundrops, 54. 
Sunflower, 65. 
Swamp Beggar-ticks, 66. 
Swamp Blueberry, 71. 
Swamp Hickory, 96. 
Swamp Honeysuckle, 73. 
Swamp Loosestrife, 55. 
Swamp Maple, 43. 
Swamp Milk-weed, 88. 
Swamp Rose, 50. 
Swamp Rose Mallow, 40. 
Swamp Saxifrage, 51. 
Swamp Thistle, 68. 
Swamp Violet, 35. 
Swamp White Oak, 97. 
Sweet Alyssum, 34. 
Sweet Birch, 98. 
Sweet Brier, 50. 
Sweet Cicely, 19, 57. 
Sweet Fern, 98. 
Sweet Flag, 103. 
Sweet Gale, 98. 
Sweet Gale Family, 98. 
Sweet Goldenrod, 64. 
Sweet-scented Bedstraw, 59. 
Sweet Vernal Grass, 129. 
Sweet White Violet, 35. 
Sweet William, 37. . 
Sweet William Catchfiy, 38. 
Symphitum, 83. 
Symphoricarpus, 58. 
Symplocarpus, 103. 
Syringa, 88. 
Tall Buttercups, 30. 
Tall Meadow Rue, 29. 
