phlox
  North American plants of the genus Phlox, having opposite leaves and
  flowers.

phytolacca decandra (Scoke, Poke, Pokeweed)
  Tall coarse perennial American herb with small white flowers followed by
  blackish-red berries on long drooping racemes; young fleshy stems are
  edible; berries and root are poisonous.

picric acid
  Poisonous, yellow crystalline solid, C6H2(no2)3Oh, used in explosives,
  dyes, and antiseptics.

piece de resistance
  Outstanding accomplishment.  Principal dish of a meal.

pilocarpus
  Small tropical American shrubs (family Rutaceae) with small greenish
  flowers.

pilocarpine muriate
  3-ethyl-4-[(3-methylimidazol-4-yl)methyl]oxolan-2-one hydrochloride
  C11H17ClN2O2

pique
  Vexation caused by a perceived slight or indignity; feeling of wounded
  pride.

pleurodynia
  Paroxysmal pain and soreness of the muscles between the ribs.  Epidemic
  disease caused by a coxsackievirus, causing pain in the lower chest and
  fever, headache, and malaise.

podophyllin
  Bitter-tasting resin from the dried root of the may apple; used as a
  cathartic.

pokeweed (pokeberry, pokeroot.)
  Tall North American plant (Phytolacca americana) with small white
  flowers, blackish-red berries, and a poisonous root.

prickly ash
  Deciduous or evergreen shrubs or trees of the genus Zanthoxylum.

probang
  Long, slender, flexible rod with a tuft or sponge at the end; used to
  remove objects from or apply medication to the larynx or esophagus.

proteid (obsolete term)
  Protein.

proud flesh
  Swollen flesh that surrounds a healing wound, caused by excessive
  granulation (Small, fleshy, bead-like protuberances—­new capillaries—­on
  the surface of a wound that is healing).

pruritus
  Severe itching, often of undamaged skin.

Prunus Virginiana (Chokecherry)
  Astringent fruit of a species of wild cherry; the bush or tree which
  bears such fruit.

pterygium
  Abnormal mass of tissue on the conjunctiva of the inner corner of the
  eye that obstructs vision by covering the cornea.

pulsatilla
  Dried medicinal herb from a pasqueflower (especially Anemone pulsatilla)
  formerly used to treat amenorrhea and dysmenorrhea.

punctilio
  Fine point of etiquette.  Precise observance of formalities.

purpura
  Hemorrhages in the skin and mucous membranes having the appearance of
  purplish spots or patches.

pyemia
  Septicemia (blood poisoning) caused by pyogenic (producing pus)
  microorganisms in the blood, often resulting in the formation of
  multiple abscesses.

pyrogallic Acid
  White, toxic crystalline phenol, C6H3(Oh)3, used as a photographic
  developer and to treat certain skin diseases.