UMass Extension Weed Herbarium
| Common Name | Scientific Name | Family Name | |
|---|---|---|---|
| peavine, everlasting | Lathyrus latifolius | Fabaceae (Leguminosae) - Pea or Bean Family | |
| pennycress, field | Thlaspi arvense | Brassicaceae (Cruciferae) - Mustard Family | |
| peppergrass, field | see - pepperweed, field | ||
| peppergrass, wild | see - pepperweed, Virginia | ||
| pepperweed, field | Lepidium campestre | Brassicaceae (Cruciferae) - Mustard Family | |
| pepperweed, Virginia | Lepidium virginicum | Brassicaceae (Cruciferae) - Mustard Family | |
| piemaker | see - velvetleaf | ||
| pigeon berry | see - pokeweed, common | ||
| pigweed, livid | Amaranthus lividus | Amaranthaceae - Amaranth Family | |
| pigweed, redroot | Amaranthus retroflexus | Amaranthaceae - Amaranth Family | |
| pigweed, spiny | see - amaranth, spiny | ||
| pilewort | Erechtites hieraciifolia | Asteraceae (Compositae) - Aster or Sunflower Family | |
| pimpernel, scarlet | Anagallis arvensis | Primulaceae - Primrose Family | |
| pineappleweed | Matricaria matricariodes | Asteraceae (Compositae) - Aster or Sunflower Family | |
| pinkweed | see - smartweed, Pennsylvania | ||
| plantain, broadleaf | Plantago major | Plantaginaceae - Plantain Family | |
| plantain, buckhorn | see - plantain, narrowleaf | ||
| plantain, common | see - plantain, broadleaf | ||
| plantain, dooryard | see - plantain, broadleaf | ||
| plantain, English | see - plantain, narrowleaf | ||
| plantain, narrowleaf | Plantago lanceolata | Plantaginaceae - Plantain Family | |
| poison ivy | Toxicodendron radicans | Anacardiaceae - Cashew Family | |
| poke | see - pokeweed, common | ||
| pokeberry | see - pokeweed, common | ||
| pokeweed, common | Phytolacca americana | Phytolaccaceae - Pokeweed Family | |
| poor man's weatherglass | see - pimpernel, scarlet | ||
| porcelainberry | Ampelopsis brevipedunculata | Vitaceae - Grape Family | |
| portulaca , wild | see - purslane, common | ||
| potato bean | see - groundnut | ||
| purpletop | Tridens flavus | Poaceae (Graminae) - Grass Family | |
| purslane, common | Portulaca oleracea | Portulacaceae - Purslane Family | |
| pursley | see - purslane, common | ||
| pussytoes, field | Antennaria neglecta | Asteraceae (Compositae) - Aster or Sunflower Family | |
| quackgrass | Elytrigia repens | Poaceae (Graminae) - Grass Family | |
| quaker ladies | see - bluets | ||
| Queen Anne's lace | see - carrot, wild | ||
| quickweed | see - galinsoga, hairy | ||
| radish, wild | Raphanus raphanistrum | Brassicaceae (Cruciferae) - Mustard Family | |
| ragged robin | Lychnis flos-cuculi | Caryophyllaceae - Pink Family | |
| ragweed , common | Ambrosia artemisiifolia | Asteraceae (Compositae) - Aster or Sunflower Family | |
| ragweed, giant | Ambrosia trifida | Asteraceae (Compositae) - Aster or Sunflower Family | |
| ragweed, great | see - ragweed, giant | ||
| ragwort | see - groundsel, common | ||
| ragwort, tansy | Senecio jacobaea | Asteraceae (Compositae) - Aster or Sunflower Family | |
| raspberry, purple-flowering | Rubus odoratus | Rosaceae - Rose Family | |
| raspberry , wine | see - wineberry, wine raspberry | ||
| rattleweed, cockscomb | see - yellow-rattle | ||
| redtop, tall | see - purpletop | ||
| reed, common | Phragmites australis | Poaceae (Graminae) - Grass Family | |
| ribgrass | see - plantain, narrowleaf |