8. Scutellaria parvula Michx. (small skullcap)

Pl. 441 j–m; Map 1999

Plants with slender, inconspicuous rhizomes. Stems 8–20(–30) cm long, loosely to strongly ascending, often from a spreading base, unbranched or few-branched, glabrous or sparsely to densely pubescent with short, curved, nonglandular hairs and sometimes also longer, spreading gland-tipped hairs. Leaves sessile or nearly so (except on basal leaves, which are short-petiolate and usually absent at flowering). Leaf blades 0.5–2.0 cm long, lanceolate to ovate, broadly ovate, or more or less triangular-ovate, rounded to truncate or shallowly cordate at the base or occasionally broadly angled, rounded or bluntly pointed at the tip, the margins entire, the surfaces sparsely pubescent with short, curved hairs or more densely pubescent with short, gland-tipped hairs, sometimes also with dense sessile glands. Inflorescences of axillary flowers, these 2 per node, solitary in the axils of the upper foliage leaves. Calyces 2.0–3.5 mm long, becoming closed and enlarged to 4–5 mm at fruiting, the outer surface sparsely to moderately pubescent with short, curved, nonglandular or straight, gland-tipped hairs, sometimes also with sessile glands. Corollas 6–12 mm long, minutely nonglandular-hairy on the outer surface, bluish purple, the lower lip mottled and/or spotted with white and purple toward the base, the tube S-shaped (bent upward just above the calyx and strongly curved or oblique at or above the throat), the lateral lobes well-developed, spreading, the lower lip broadly depressed ovoid, deeply notched at the tip. Nutlets 1–4 per calyx, 0.9–1.2 mm long, more or less globose, the surface dark brown to black, densely warty or with rounded tubercles, interrupted by a broad, smooth, transverse band. 2n=20. May–July.

Scattered nearly throughout the state (eastern U.S. west to North Dakota and Texas; Canada). Glades, bottomland prairies, upland prairies, savannas, ledges and tops of bluffs, bottomland forests, and mesic to dry upland forests; also pastures, railroads, and roadsides.

The S. parvula complex, including S. nervosa, presents a good topic for a future taxonomic and phylogenetic study. Most botanists admit that the four entities involved are closely related and that S. nervosa deserves separate species rank, given its longer stems with more frequent branching and larger leaves, but the treatment of the other three taxa remains controversial. Some authors have followed Epling (1942) in treating these as three separate species, S. australis, S. leonardii, and S. parvula in the strict sense. Others, including Steyermark (1963) and the present work have followed Fernald (1945) and treated them as three varieties of S. parvula. Gleason and Cronquist (1991) chose a compromise, treating two species, S. leonardii and S. parvula, but subsuming the third taxon as a variety of S. parvula. This last approach apparently is in response to Epling’s (1942) comments that S. leonardii is morphologically similar in some ways to S. nervosa and that the two taxa sometimes are found growing in proximity. For the present, it seems prudent to follow Steyermark’s (1963) approach, with a minor nomenclatural update for the former var. leonardii, following the historical research of Goodman and Lawson (1992).