193 



Pilea, 95. 



Pimpernel, 76. 



Pine Family, 101. 



Pine-sap, 74. 



Pine-weed, 37. 



Pinls; Family, 37. 



Pinus, 101. 



Pinus resinosa, 12, 101. 



Pipewort, 114. 



Pipe wort Family, 114. 



Pipsissewa, 74. 



Pirus, 50. 



Pitcher Plant, 32. 



Pitcher Plant Family, 32. 



Pitch Pine, 101. 



Placodium, 152. 



Plaglothecium, 144. 



Plane Tree Family, 95. 



Plantaginacese, 75. 



Plantago, 75. 



Plantago Maritima, 75. 



Plantain, 75. 



Plantain Family, 75. 



Plantanacese, 95. 



Platanus, 95. 



Pleurisy-root, 88. 



Pluchea, 64. 



Plum, 48. 



Plumbaginaceae, 75. 



Poa, 126. 



Podophyllum, 31. 



Pogonatum (Polytrichium), 171. 



Pogonia, 108. 



Poison Hemlock, 57. 



Poison Ivy, 42. 



Poison Sumach, 42. 



Poke, 89. 



Poke Milk-weed, 88. 



Poke-weed Family, 89. 



Polemoniacese, 84. 



Polygala, 44. 



Polygalacese, 44. 



Polygonacese, 91. 



Polygonatum, 112. 



13 



Polygonum, 91. 

 Polygonum Careyl, 12, 91. 

 Poly ides, 160. 

 Polypodium, 133. 

 Polypody, 133. 

 Polypogon, 123. 

 Polysiphonia, 158. 

 Poiytrichese, 140. 

 Polytrichnm, 140, 171. 

 Pond-weed Family, 104. 

 Pontederia, 114. 

 Pontederiacese, 114. 

 Poor-man's Weather-glass, 76. 

 Poplar, 100. 

 Poppy Family, 32. 

 Populus, 100. 

 Porphyra, 162. 

 PorphyresB, 162. 

 Portulaca, 39. 

 Portulacaceaj, 39. 

 Potamogeton, 104. 

 Potentilla, 48. 



Potentilla tridentata, 12, 49. 

 Poterium, 48. 

 Pottia, 139. 



Pottia (Gymnostomum), 170. 

 Pottieae, 139. 

 Poverty Grass, 125. 

 Prairie Willow, 99. 

 Preissia, 144. 

 Prickly Pear, 55. 

 Prickly Poppy, 32. 

 Prim, 88. 

 Primulaceae, 75. 

 Primrose Family, 75. 

 Primrose-leaved Violet, 35. 

 Px'ince's Feather, 15, 91. 

 Prince's Pine, 74. 

 Privet, 88. 

 Proserpinaca, 53. 

 Prunus, 47. 

 Pterigynandrum, 172. 

 Pteris, 133. 

 PtUidium (Belpharozia,) 145. 



