Answer: pinnules

AnswerCrossword Clue
pinnulessecondary pinna, one of the pinnately disposed divisions of a bipinnate leaf
pinnulesPINNULE, a pinnate part or organ, also PINNULA
pinnulesmetal plate with a small hole in it, used as a sight in a quadrant
pinnulesa. part or organ resembling a barb of a feather, a fin, or the like b. finlet