8c. ssp. pilosa

P. pilosa var. amplexicaulis (Raf.) Wherry

P. pilosa var. virens (Michx.) Wherry

P. argillacea Clute & Ferris

Plants sometimes with 1 or a few vegetative stems. Stems with 9–14 nodes, usually lacking axillary branches, sparsely to densely pubescent with nonglandular hairs below the midpoint, grading to gland-tipped hairs only toward the tip. Leaves opposite, linear to less commonly narrowly elliptic toward the stem base, grading to narrowly lanceolate or lanceolate toward the stem tip, the bases of the upper leaves not cordate, the lowermost hairy to nearly glabrous, the uppermost moderately to densely pubescent with sometimes gland-tipped hairs, the largest leaves 3.5–7.5 cm long and 2–14 mm wide. Leaves subtending flower clusters linear-lanceolate to lanceolate, the bases not cordate. Inflorescences pubescent with fine, gland-tipped hairs (rarely nonglandular-hairy). Calyces 7–12 mm long, glandular-hairy. Corollas with the tube pubescent with at least some of the hairs gland-tipped, rarely glabrous or nearly so, the lobes 7–14 mm long and 4–10 mm wide. 2n=14. April–May.

Scattered to common in the southern half of the state, disjunct in Nodaway and Scotland Counties (eastern U.S. west to Iowa and Texas; Canada). Glades, savannas, upland prairies, bottomland forests, mesic to dry upland forests, bases, ledges, and tops of bluffs, margins of sinkhole ponds, banks of streams and rivers, and fens; also pastures, old fields, ditches, railroads, and roadsides.

Steyermark (1963) recognized rare plants of P. pilosa ssp. pilosa in Missouri with relatively coarse, nonglandular hairs as P. pilosa var. amplexicaulis, and listed P. pulcherrima (Lundell) Lundell in synonymy. The present author considers var. amplexicaulis a synonym of P. pilosa ssp. pilosa, but recognizes P. pulcherrima as a distinct species not occurring in Missouri (a narrowly endemic tetraploid taxon in eastern Texas).