1C P R 



Hum. ramosissimum (branching knotgrass.) tenue (slend- 

 er knotgrass.) lapathifolium. punctatum (water-pepper, 

 biting knotweed.) mite (tasteless knotweed.) -Virginia- 

 wttn. viviparum. coccineum (lake knotweed.) persica- 

 ria (ladies' thumb, heart-spot knotweed.) pensylvanieum 

 (knee knotweed.) orientate (prince's feather.) articula- 

 tum (joint- weed.) sagittatmn (prickly knotweed.) ari- 

 folium (halbert knotweed.) jagopyrum (buck-wheat*) 

 'convolvulus (bind knotvveedv) scandens (climbing knot- 

 >veed.) cilinode. 



184. POLYMNIA, 49. 55. 



canadensis (white leaf-cup.) imedalia (yellow leaf-cup. ) 

 231. POLYPODIUM, 55. 5. 



vulgare (polypod. Ju. ^.) frond deeply pinnatifid ; di- 

 visions lance-linear, obtuse, crenulate. hexagonopterum. 

 connectile. calcarcum. 



POLYTRICHUM, 56. 4. 



jnniperinum (hair-cap moss. M. i(.) leaves lance-lin 

 ear, pointed, entire, inflected at the dges, rough on the 

 keel : capsule square, on a flat receptacle, 

 piliferum* perigoniale* pensylvanicum. 



PONTEDERIA, 6. 17. 



cordata (pickerel weed. b. Ju, if.) leaves heart-oblong, 

 obtuse : spike many-floweredy compact. 



2113. POPULUS, 50. 99. 



tremuloides (white poplar, american aspen. Ap. ^ ) 

 leaves heart-roundish, abruptly acuminate, tooth-serru- 

 Jate, glabrous, grandidentata (tree poplar.) betidifolia 

 (birch-leaf poplar.) angidata (balm-of-gilead, water pop- 

 lar, cotton wood, batsamifera (balsam poplar.) candi- 

 cans. laevigata (cotton tree.) heterophylla (various-leav- 

 ed poplar.) dilatata (lombardy poplar, Italian poplar. 



1313. PORCELIA, 52. 76. 

 triloba (custard apple.) 



1010. PORTULACCA,.54. 89. 



oleracea (purslane y. J O.) leaves wedge -form : flow 

 ers sessile. 



