- pitcher-plant
- plagiotropic
- plane-tree
- phyllotaxis
- phytocoenosis
- phytogeography
- picotee
- pimpernel
- pinkster flower
- pinnae
- pipal
- plagiotropous
- pleiocotyl
- pleiocotyledony
- pleiophyllous
- plum
- plum-tree
- plumbago
- plumule
- plane
- plantain
- platan
- platinum blonde
- pleiosporous
- pleiocotyledonary
- pleiopetalous
- pleuranthous
- plumular
- plurisporous
- plagiotropism
- planipetalous
- pod
- podocephalous
- poinciana
- pointel
- poison ivy
- poke-berry
- pokeweed
- polemoniaceae
- polio
- pollination
- pollinic
- polyandrous
- polycarpellary
- polydelphous
- polygala
- polygamous
- polygonum
- polymerous
- polypetalous
- polystelic
- pond-lily
- poon
- positive
- pollakanthic
- pollen
- pollinarium
- polliniferous
- pollinium
- polster
- polyadelphous
- polycarpous
- polygynous
- polyphyllous
- polypody
- polyrhizal
- polysepalous
- polysporous
- pond-weed
- poplar
- poppy
- pouch
- prefoliation
- premorse
- prickle
- primine
- primula
- privet
- proangiosperme
- procarp
- primrose
- procambium
- proembryo
- propagule
- prophloem
- prosenchyma
- prostrate
- prophyllum
- proterandric
- proterandrous
- prothallial
- prothallium
- protonema
- pruinose
- psylla
- pteridium
- pteridology
- proterandry
- proteranthous
- prothalloid