4. Scutellaria incana Biehler (downy skullcap, hoary skullcap)

S. incana var. punctata (Chapm.) C. Mohr

Pl. 442 g, h; Map 1995

Plants sometimes with short rhizomes. Stems 40–80(–120) cm long, erect or ascending, sometimes from a short, spreading base, unbranched or occasionally few-branched, densely pubescent with short, upward-curved, nonglandular hairs, often also with sessile glands. Leaves with the petioles 5–30 mm long, winged toward the tip. Leaf blades 4–11 cm long, ovate to elliptic (the uppermost narrowly so), angled or tapered at the base, those of the lowermost leaves occasionally asymmetrically rounded or shallowly cordate (but with a wedge of tissue in the notch extending down the petiole tip), angled or tapered to a sharply pointed tip, the margins finely to occasinally coarsely and more or less bluntly toothed, the upper surface green and sparsely to moderately pubescent with minute, curved, nonglandular hairs, mostly along the main veins or toward the blade base, the undersurface grayish green and moderately to densely pubescent with short, curved and more or less straight, nonglandular hairs, more densely so along the veins, both surfaces also with sessile glands. Inflorescences of slender racemes, these mostly terminal, sometimes in a cluster of 3 from the stem tip, the flowers 2 per node, solitary in the axils of bracts, the bracts 4–6 mm long, narrowly elliptic to lanceolate. Calyces 2–3 mm long, becoming closed and enlarged to 5–6 mm at fruiting, the outer surface densely pubescent with short, appressed to somewhat woolly, nonglandular hairs, sometimes also with sessile glands. Corollas 15–25 mm long, moderately to densely pubescent with minute, appressed to somewhat woolly, nonglandular hairs on the outer surface, often also with sessile glands, blue to bluish purple or purple above a usually white tube, the lower lip with a white patch toward the base, the tube S-shaped (bent upward just above the calyx and strongly curved or oblique at or above the throat), lacking a ring of hairs in the throat, the lateral lobes relatively well-developed, ascending, the lower lip broadly fan-shaped to nearly semicircular, usually shallowly notched at the tip. Nutlets 1–4 per calyx, 1.5–2.0 mm long, more or less globose, the surface dark brown, finely warty or with dense, low, rounded tubercles. 2n=30. June–September.

Scattered, mostly in the Ozark and Ozark Border Divisions, north locally to Monroe and Pike Counties (eastern U.S. west to Iowa, Kansas, and Texas). Mesic to dry upland forests, banks of streams, rivers, and spring branches, fens, bases, ledges, and tops of bluffs; also ditches and roadsides.

Steyermark (1963) and some other authors have attempted to separate plants from throughout the species range with the leaf blades densely hairy on the undersurface (var. incana) form those in the southeastern United States with the pubescence sparser and mainly confined to the veins (var. punctata). Although striking in their extremes, these variants are not sharply distinct, and numerous intermediates exist.