How many letters does the top answer for “the doctrine of the generation of plants.” have?

The most common answer is phytogenesis (12 letters).

Crossword clue: the doctrine of the generation of plants.

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

phytogenesis 12 letters web-def

The doctrine of the generation of plants.

phytogeny 9 letters web-def

The doctrine of the generation of plants.

the doctrine or science of generation. 50% similar → genesiolgy