5. Scutellaria lateriflora L. (mad dog skullcap)
Pl. 442 i, j;
Map 1996
Plants with
slender rhizomes. Stems 15–60(–100) cm long, ascending, sometimes from a
spreading base, usually branched, glabrous or sparsely pubescent on the angles
with short, upward-curved, nonglandular hairs. Leaves with the petioles 5–30 mm
long. Leaf blades 1–11 cm long, lanceolate to ovate, rounded to truncate or
shallowly cordate at the base, sharply pointed at the tip, the margins finely
to relatively coarsely toothed, the surfaces glabrous or the undersurface
sparsely pubescent with short, appressed or curved, nonglandular hairs, the
surfaces usually lacking sessile glands. Inflorescences of slender racemes,
these mostly axillary, occasionally reduced to solitary axillary flowers, the
flowers 2 per node, solitary in the axils of bracts or foliage leaves, the
bracts 8–13 mm long and narrowly ovate toward the raceme base, progressively
shorter and narrower toward the tip. Calyces 1.5–2.5 mm long, becoming closed
and enlarged to 3–4 mm at fruiting, the outer surface moderately to densely
pubescent with minute, curved, nonglandular hairs. Corollas 5–8 mm long,
densely pubescent with minute, nonglandular hairs on the outer surface, pale
blue or light bluish purple, rarely white, the lower lip usually lacking spots
or mottling, the tube not S-shaped (nearly straight above the calyx, somewhat
oblique at or above the throat), the lateral lobes not well-developed,
ascending, the lower lip relatively short, oblong, usually very slightly
notched at the tip. Nutlets 1–4 per calyx, 1.0–1.3 mm in diameter,
depressed-globose or broadly obovoid, the surface yellowish brown, densely warty
or with low, rounded tubercles. 2n=88. June–October.
Scattered nearly
throughout the state (nearly throughout the U.S. [including Alaska]; Canada).
Banks of streams and rivers, margins of ponds, lakes, and sinkhole ponds,
bottomland forests, bases of bluffs, sloughs, marshes, and swamps; also
ditches; occasionally epiphytic on floating logs, hummocks of Carex, and
the lower trunks of Taxodium.
Rare plants with
white corollas have been called f. albiflora (Farw.) Fernald.