The building blocks of English

Affixes

pterido-

A fern.

Greek pteris, pterid‑, fern.

A pteridophyte (Greek phuton, plant) is a member of the Pteridophyta, a division of flowerless green plants that comprises the ferns and their relatives; pteridology is the study of ferns and related plants; and a pteridosperm is a fossil plant which is intermediate between the ferns and seed-bearing plants, dying out in the Triassic period.