According to the rules, "With a full night’s rest (8 hours of sleep or more), you recover 1 hit point per character level. Any significant interruption during your rest prevents you from healing that night.", but some Types, like Plants or Oozes, do not rest: does it mean they are prevented from healing by the passing of time?
Constructs and Undead with no Intelligence cannot heal themselves, but no such clauses are written in the list of Plants', Oozes' or other not-resting Creatures' traits.
