Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.
The Shade Border Arbor, completed a few years ago, has given our gardeners a wonderful new structure to use as support for some interesting vines. One of them is this member of the bellflower family (Campanulaceae). Commonly called bonnet bellflower, or codonopsis—(its botanical name is Codonopsis lanceolata—it has taken a few years to get properly established and it is now producing its first flowers.
Looking for all the world like a tropical plant, suitable only for a greenhouse, it is actually hardy in this climate. The stems might be killed to the ground in winter, but it grows back strongly from its tough root system each spring.
The flower buds are dimpled, greenish-white puffs—which resemble barn owl faces at certain angles!—and they open to reveal purple-lined petals and a specked interior.
The walls of the flower are so thin that they are translucent and the odd dapples of sunlight that filter through the surrounding trees cause them to light up like delicate lanterns. When you venture to the Shade Border, look for them behind the middle pillar in this last shot.
Native to East Asia, the bonnet bellflower is an adaptable plant which will grow in full sun or part shade.