How many letters does the top answer for “lettuce with long dark-green leaves in a loosely packed elongated head” have?

The most common answer is cos (3 letters).

Crossword clue: lettuce with long dark-green leaves in a loosely packed elongated head

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

cos 3 letters wn-def

lettuce with long dark-green leaves in a loosely packed elongated head

romaine 7 letters wn-def

lettuce with long dark-green leaves in a loosely packed elongated head