頭狀花序 Capitulum 頭狀花序,形容花軸短縮成盤狀,頂端著生大量無花柄之小花,如:銀合歡、向日葵。 Refers to a type of inflorescence with a dense terminal cluster of sessile flowers on a short disc-shaped flower axis, such as White Popinac and sunflower.