How many letters does the top answer for “that branch of paleontology which treats of fossil plants.” have?

The most common answer is paleobotany (11 letters).

Crossword clue: that branch of paleontology which treats of fossil plants.

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

paleobotany 11 letters web-def

the study of fossil plants