This native perennial plant is 1–2½' tall, branching occasionally. The stems are light green to pale reddish green, 4-angled, and hairless or sparsely canescent; they have a tendency to sprawl. The blades of the opposite leaves are up to 3" long and 2" across; they are cordate-ovate to broadly lanceolate, hairless, and coarsely serrated along the margins. On the upper surface of each leaf blade, there is a conspicuous network of veins. The petioles of the leaves are light green to pale reddish green, slender, and up to 1" long. Both terminal and axillary racemes of flowers are produced by the upper stems. Each slender raceme is up to 6" long, consisting of about 6-7 pairs of flowers; the axillary racemes spread outward from their stems. Underneath each flower, there is a short leafy bract. Each flower is up to 1/3" in length, consisting of a tubular corolla and a tubular calyx. The corolla is pale blue, lavender, or white; it has short upper and lower lips. The lower is lip is often white, while the upper lip is often a slightly darker color. The calyx is light green or pale reddish green, hairless or sparsely canescent, and divided into 2 shallow lobes. Behind the upper lobe is a short dish-like projection that is typical of Scutellaria spp. (Skullcaps). The pedicel of each flower is slender and short. The blooming period occurs during the summer and early fall, lasting about 1½–2 months for a colony of plants. Usually, only a few flowers are in bloom at the same time in a raceme. There is no noticeable floral scent. Each flower is replaced by an oddly-shaped seed capsule that contains 4 nutlets. This capsule consists of 2 lobes that are joined at the base, but spread slightly apart from each other at their tips; these lobes are somewhat flattened and round along their margins. The root system consists of a taproot and either rhizomes or stolons. Small colonies of plants are often produced from the rhizomes or stolons.
Mad-Dog Skullcap (Scutellaria lateriflora), http://www.illinoiswildflowers.info/wetland/plants/md_skullcap.htm (accessed January 23, 2017).