Pachyrhizus – 2 clippings
Paeonia – 2 clippings
Paint – 3 clippings
Paleobotany – 16 items, including Natural History 1984 “Ancient Flowers for the Faithful,” The Times (London) 1980 “Microbiology: The oldest fossils.”
Palmae 1 – 30 clippings, including The Agricultural News 1906 “The Economic Uses of the Palms.”
Palmae 2 – 26 items, including The Agricultural News 1908 “Palm Trees and Their Uses.”
Pandanus – 3 clippings
Papaver – 11 clippings, including Natural History 1980 “The Versatile Opium Poppy.”
Papaveraceae – 1 clipping
Paper 1 – 38 items, including The Agricultural News 1913 “New Sources of Paper.”
Paper 2 – 14 items, including Natural History 1937 “The Story of Paper.”
Paper 3 – 42 items, including American Forestry 1917 “Forestry and the Paper Industry.”
Paper 4 – 19 items, including The Boston Globe 1925 “The Invention of Writing and Discovery of Metals.”
Paper 5 – 23 items, including The New York Times 1981 “Book Keeping in New York.”
Paper Pulp – 15 clippings, including American Forestry 1920 “Paper pulp from seaweed”.
Parkinsonia – 9 items, including The Times (London) 1982 “Some acid words from mummy,” Harvard Gazette 1979 “Historic records: Legal documents could be oldest from Palestine.”
Parmentiera – 1 clipping
Passiflora – 7 items, including The Agricultural News 1903 “The Bell Apple.”
Paullinia – 18 items
Pea – 4 clippings
Peach – 6 clippings
Peanuts 1 (up to 1930s) – 31 items
Peanuts 2 (1940s–1980s) – 26 items
Pear – 16 items
Peat – 18 items, including Natural History 1982 “Beneath the blanket bogs of Britain.”
Pecan – 7 items
Pedicularis – 1 clipping
Peltostigma – 2 clippings
Penicillin – 7 clippings
Pentadesma – 1 clipping
Pepper – 11 items
Peppermint – 2 items
Perfumes – 34 clippings, including Boston Traveler 1951 “Making, selling perfume grosses 100 Million yearly,” Clipper 1979 “The World’s Rare Fragrances.”
Periploca – 1 clipping
Persea – 9 clippings, including The Agricultural News 1909 “The Avocado Pear.”
Persimmon – 2 clippings
Pesticides – 14 clippings, including The New York Times 1980 “Turkish Farmers Turn Bitterly from Opium Poppy.”
Peyote – 31 items, including The Florida Times–Union “Vicious Drug Plays Havoc with Navajos.”
Phaseolus – 12 clippings, including The Agricultural News 1905 “Lima Beans.”
Phleum – 1 item
Phoenix – 24 clippings, including Geographical Review 1926 “The Distribution of the Date Palm.”
Phoradendron – 2 clippings
Phormium – 10 clippings, including The Agricultural News 1918 “New Zealand Hemp.”
Photinia – 1 clipping
Physiology – 8 clippings, including Newsweek 1980 “Hormones for Profit.”
Physostigma – 1 clipping
Phytelephas – 6 clippings
Phytochemistry – 4 items
Phytolacca – 6 items
Picea – 10 items, including Natural History 1938 “The Rarest American Spruce.”
Pickles – 3 items
Pilocarpus – 1 item
Pimenta – 5 items
Pinckneya – 3 items
Pine – 13 items
Pineapple – 24 items
Pinus – 41 items, including American Forestry 1917 “The Slash Pine.”
Piper – 17 items, including New York Times 1971 “Betel–Leaf Chewers in Karachi Joyfully Await a Taste of Peace.”
Pipes – 14 items, including New York Times 1979 advertisement “New – Fashionable Pipes for the Ladies (you need not inhale).”
Pisonia – 1 item
Pistacia – 7 items
Pisum – 1 item
Pithecolobium – 5 items, including American Forestry 1916 “The Saman or Rain Tree.”
Plant Lore – 15 items, including The New York Times Sunday 1938 “Finds Death Trees, Feared by Indians.”
Plantago – 5 items
Plastics – 3 items
Plantus – 3 items
Plum – 7 items
Podophyllum – 3 items
Poinsettia – 1 item
Poisons 1 (up to 1930s) – 40 items, including The Garden 1921 “Squills as a Rat Poison,” The Boston Globe 1924 “Two are Killed by Toadstools.”
Poisons 2 – 23 items
Poisons 3 – 17 items, including The New York Times 1983 “The Deepening Mystery of Yellow Rain.”
Pollination – 1 item
Polygala – 2 items
Polygonum – 2 items
Polymnia – 1 item
Pomaderris – 1 item
Pontederia – 2 items
Potato 1 – 34 items, including Science News Letter 1929 “Earliest Description of Potatoes.”
Potato 2 – 35 items, including The New York Times 1938 “Researchers work on sticky potato that traps insects.”
Preservatives – 3 items, including The New York Times Sunday 1978 “Dried Blossoms Will Last Forever”.
Preserves – 6 items, including The Garden Magazine 1916 “The Guava – A Substitute for Gooseberries in Florida.”
Primula – 2 items
Prioria – 1 item
Propagation – 1 item
Prosopis – 11 items, including The New York Times 1982 “Mesquite: Bad Press but Great Flavor.”
Protein – 9 items
Prunus – 24 items
Pseudotsuga – 11 items
Psophocarpus – 13 items, including Life Magazine 1980 “Food for Tomorrow: From odd pods that grow in the tropics to lobsters bred in boxes.”
Pteridium – 6 items
Puccoon – 1 item
Pumpkins – 8 items
Punica – 4 items
Puya – 2 items
Pyrethrum – 4 items
Pyrola – 2 items
Pyrus – 7 items