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.