Flowers Blue or Purple

Leaves are opposite
Plant with mint odor	Mountain pennyroyal
Plant without a mint odor
One large flower at tip of stem	Sierra gentian
Several flowers along stem
Flowers more than 1 inch long	Showy penstemon
Flowers smaller; in whorls	Rydberg's penstemon
Leaves are alternate
Flowers about 3 inches across	Western blue flag
Flowers less than 3 inches across
Flowers daisy-like with lavender outer part	Hoary aster
Flowers not daisy-like
Plant less than 1 foot high; flowers small	Blue balls
Plant more than 1 foot high; flowers showy
Flowers rose-violet; roadsides	Fireweed
Flowers indigo-blue; boggy areas
Flowers with a hood-like cap	Monk's hood
Flowers with a tail-like spur	Mountain larkspur