is a variable plant; several subspecies are recognized, and specimens from different locations show a range of characteristics, in such aspects as leaf hairiness, leaf edges (entire or serrate), leaf shape, leaf color and bract properties.
Stems and leaves may be light green to dark grey in color (sometimes with purple tints), and they usually have a sparse covering of short hairs. Stems grow generally upwards, branch readily, and usually bear a single, spherical flower cluster, about one inch wide, with a whorl of leafy, green to purple bracts underneath. Individual flowers consist of a hairy, purple, five-lobed calyx and a two-lipped corolla. The upper lip is divided into two lobes, angled upwards, and the lower lip is divided into three lobes, curved backwards. The corolla contains four stamens and a two-lobed style, all exserted.Ssp pallida
, found mostly in California, has white or very pale purple flowers, while the more widespread ssp glauca
has darker purple or reddish flowers, and grey-green (glaucous) stems.