produces stout, leafy stems topped by spherical, terminal clusters of 25 to 100 white to blue flowers. Leaves and stems are usually glandular, with a dense coating of short, sticky hairs. Leaves are pinnately lobed; those around the base and along the lower stems are divided into several dozen narrow pointed lobes, while those higher up have just a few lobes, generally longer.
Each flower is supported by a green, lobed calyx, and consists of five linear to oblong petals, five slightly protruding stamens and a longer, two-lobed style. The corolla tube is entirely enclosed by the calyx.
There are many subspecies, differing in corolla length, corolla color, hairiness, cluster width, petal shape and petal width.