balloon-flower

…As the scientific name Platycodon (broad bell) suggests, the corolla is broad and bell-shaped, with the lobes curling back. Before blooming, the flower has a closed corolla resembling an inflated balloon, so it is also called balloon flower. The fruit is a capsule, with the inner calyx lobes dehiscing into five lobes. …

*Some of the terminology that mentions "balloon-flower" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…学名のPlatycodon(広い鐘)の示すとおり，花冠は広い鐘形で裂片は反り返る。開花前の花は花冠が閉じてふくらんだ風船を思わせるので，英名をballoon‐flowerともいう。果実は蒴果（さくか）で，萼裂片の内側が5片に胞背裂開する。…

※「balloon-flower」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報