193 
Pilea, 95. Polygonum, 91. 
Pimpernel, 76. _ Polygonum Careyi, 12, 91. 
Pine Family, 101. Polyides, 160. 
Pine-sap, 74. Polypodium, 133. 
Pine-weed, 37. | Polypody, 133. 
- Pink Family, 37. Polypogon, 123. 
Pinus, 101. Polysiphonia, 158. 
Pinus resinosa, 12, 101. Polytriches, 140. 
Pipewort, 114. Polytrichum, 140, 171. 
Pipewort Family, 114. Pond-weed Family, 104. 
Pipsissewa, 74. Pontederia, 114. 
Pirus, 50. Pontederiacee, 114. 
Pitcher Plant, 32. Poor-man’s Weather-glass, 76. 
Pitcher Plant Family, 32. Poplar, 100. 
- Pitch Pine, 101. Poppy Family, 32. 
Placodium, 152. Populus, 100. 
Plagiothecium, 144. Porphyra, 162. 
Plane Tree Family, 95. Porphyree, 162. 
Plantaginacee, 75. Portulaca, 39. 
Plantago, 75. Portulacacee, 39. 
Plantago Maritima, 75. Potamogeton, 104. 
Plantain, 75. Potentilla, 48. 
Plantain Family, 75. Potentilla tridentata, 12, 49. 
Plantanacee, 95. Poterium, 48. 
Platanus, 95. Pottia, 139. 
-Pleurisy-root, 88. Pottia (Gymnostomum), 170. 
Pluchea, 64. Pottiezx, 139. 
Plum, 48. - Poverty Grass, 125. 
Plumbaginacee, 75. Prairie Willow, 99. 
Poa, 126. Preissia, 144. 
Podophyllum, 31. Prickly Pear, 55. 
Pogonatum (Polytrichium), 171. Prickly Poppy, 32. 
Pogonia, 108. Prim, 88. 
Poison Hemlock, 57. Primulacee, 75. 
Poison Ivy, 42. Primrose Family, 75. 
Poison Sumach, 42. Primrose-leaved Violet, 35. 
Poke, 89. Prince’s Feather, 15, 91. 
Poke Milk-weed, 88. Prince’s Pine, 74. 
Poke-weed Family, 89. Privet, 88. 
Polemoniacee, 84. Proserpinaca, 53. 
Polygala, 44. Prunus, 47. ’ 
Polygalaceer, 44, Pterigynandrum, 172. 
Polygonacee, 91. Pteris, 133. 
Polygonatum, 112. Ptilidium (Belpharozia,) 145. 
18 
