Pale smartweed. 274
Paperflower. 128
Penstemon albidus. 230
Physalis hederiefolia. 93
Physalis longifolia. 94.
Phytolacca americana. 46.
Pitcher's salvia. 235
Plains blackfoot. 131
Plains chinese-lantern. 90
Plains daisy. 169
Plains hymenoxys. 127
Plains larkspur. 225
Plains yellow evening primrose. 20
Plantago patagonica. 266.
Plantago rhodosperma. 265
Plume dalea. 213
Poison ivy. 270
Pokeweed, Pokeberry. 46
Polanisia dodecandra. 8
Polygala alba. 268
Polygonum lapathifolium. 274
Prairie groundcherry. 93
Prairie spiderwort. 1
Prairie sunflower. 155
Prickly lettuce. 179
Prickly sowthistle. 178
Proboscidea louisianica. 234
Psilostrophe villosa. 128
Psoralea cuspidata. 209
Psoralea tenuiflora var. tenuiflora. 203
Puncture vine. 49
Purple poppy mallow. 58
Purple prairie clover. 281
Pyrrhopappus grandiflorus. 176.