Historical Rules · 1 February 2013
Rule 205.3c
Official source text from the 1 February 2013 Rules release
If a card with multiple card types has one or more subtypes, each subtype is correlated to its appropriate card type. Example: Dryad Arbor's type line says "Land Creature -- Forest Dryad." Forest is a land type, and Dryad is a creature type.