Scutellaria lateriflora L. - Mad-dog Skullcap

Scutellaria lateriflora plant

Family - Lamiaceae

Stems - Erect to reclining, single or multiple from base, from fibrous roots, to 1m tall, branching, 4-angled, becoming purple in strong sun, hollow, glabrous to pubescent in inflorescence.

Leaves - Opposite, petiolate, decussate. Petioles to 1.5cm long, with a few sparse appressed hairs, with an adaxial groove, often purple in strong sun. Blades ovate, acute to acuminate, serrate to crenate-serrate, truncate to rounded at the base, to +2cm broad, +4cm long, mostly glabrous, light green below, dull green above. Veins impressed above, expressed below. Margins of serrations sparse antrorse strigillose.

Scutellaria lateriflora leaves

Inflorescence - Terminal and axillary bracteate racemes to +10cm long. Flowers secund and paired. Pedicels -1mm long in flower, puberulent. Each pedicel subtended by a bract. Bracts reduced upward. Axis of raceme glabrous or with antrorse hairs on the angles.

Flowers - Corolla to +7mm long, bilabiate, blue-purple (rarely white), pubescent externally. Lower lip single-lobed, rounded to emarginate at the apex, to 2.3mm broad, -2mm long. Upper lip shallowly 3-lobed. Lobes rounded. Central lobe slightly emarginate, shorter than lower lip, galeate. Stamens 4, didynamous, included, adnate in lower 2/3 of the corolla tube. Filaments white, sparsely pubescent, +/-3mm long. Anthers yellow, .4mm long. Style exserted between the upper pair of stamens, included under the galea, glabrous, translucent, +/-4.5mm long. Calyx bilabiate (each lip single-lobed and rounded), 2.2mm long in flower, accrescent, puberulent (sometimes glandular). Dorsal protuberance of calyx -1mm long and broad. Ovary 4-lobed, subtended by a disk-shaped nectary, .5mm broad in flower. Lobes of ovary in an "auditorium" fashion, with two lobes raised higher than the other two.

Scutellaria lateriflora flowersFlowers.

Scutellaria lateriflora calyxCalyx.

Scutellaria lateriflora fruitsFruits.

Flowering - June - October.

Habitat - Wet areas.

Origin - Native to U.S.

Other info. - This distinctive species can be found throughout Missouri. The plant is easy to ID while in flower because of its small paired flowers and habitat.
Traditionally this species was widely used as a remedy for many ailments ranging from rabies to epilepsy. The plant does contain a flavinoid, Scutellarin, which is a proven sedative and antispasmodic.

Photographs taken in Brown Summit, NC., 8-2-02.


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