Narrowleaf Skullcap, Narrow-leaf Skullcap, Narrow-leaved Skullcap: Scutellaria angustifolia ssp. angustifolia (Synonyms: Scutellaria angustifolia var. angustifolia, Scutellaria veronicifolia) - Flowers paired from the leaf axils. Corolla deep blue-violet and 24-28 mm long. Stems arise singly or in small clusters from 10-30 cm high. Plants of drier or rocky uplands.
Hooded Skullcap, Marsh Skullcap, Willow-weed Skullcap: Scutellaria galericulata (Synonym: Scutellaria epilobiflia)
Blue Skullcap, Hoodwort, Mad-dog Skullcap, Madweed: Scutellaria lateriflora (Synonym: Scutellaria lateriflora var. lateriflora) - Flowers in elongated racemes from the leaf axils or terminating the main stem and lateral branches. Corolla blue and 6-8 mm long. Leaves ovate to lance-ovate with broadly rounded to heart-shaped base, typically 3-8 cm long and 1.5-5 cm wide. Stems 20-80 cm high. Plants of moist bottomlands.