白色、淡黄色、紫色、紫红色
The flowers have a long pedicel, a tubular calyx with three teeth, and a corolla 11-15 mm long, white or pale yellow with a darker purple or reddish-purple helmet.
It flowers from May to August and fruits from July to September.
The stems are mostly solitary or 4-6 in number, hollow, slightly angular, and sparsely hairy or nearly hairless.