9. Liatris squarrulosa Michx.

L. scabra (Greene) K. Schum.

Pl. 269 c–e; Map 1129

Rootstock a more or less globose to ovoid corm, sometimes appearing somewhat erect and angular or irregular. Stems 25–150 cm long, moderately to densely pubescent with short, curled hairs, sometimes roughened to the touch. Basal and adjacent lower stem leaves short- to long-petiolate, the blades 8–25 cm long, 9–45 mm wide, oblanceolate to narrowly elliptic, the surfaces glabrous to densely short-hairy, green, with 1 main vein, grading abruptly to the shorter stem leaves, these mostly sessile, 2–15 cm long, narrowly oblanceolate to narrowly oblong-elliptic or sometimes linear. Inflorescences short to elongate spicate racemes, the heads mostly relatively loosely spaced (the axis visible between heads), sessile or with stalks to 15 mm long, these with only 1 or few bracts. Heads with 11–26(–28) disc florets, the terminal head not or sometimes slightly larger than the others. Involucre 7–14 mm long, broadly cup-shaped to broadly bell-shaped, with 4–6 unequal, overlapping series of bracts (the outer series appearing progressively shorter). Involucral bracts broadly obovate to oblong-spatulate, all but the innermost series spreading or recurved at the tip, mostly with relatively narrow, thin, pale to transparent margins, the margins or entire bract sometimes strongly purplish-tinged, nearly entire to shallowly scalloped (sometimes also minutely irregular), the main body appearing flat or very slightly swollen just below the tip. Corollas 9–12 mm long, the tube hairy on the inner surface. Pappus bristles barbed. Fruits 3.5–5.5 mm long. 2n=20. August–November.

Scattered mostly in the Ozark and Ozark Border Divisions (Ohio to Florida west to Missouri and Texas). Glades, bases, ledges, and tops of bluffs, savannas, openings of mesic to dry upland forests, and rarely upland prairies; also ditch banks, fencerows, pastures, railroads, and roadsides.

Liatris squarrulosa is part of a taxonomically difficult species complex that also includes L. aspera and L. scariosa. For further discussion, see the treatment of the latter species. Most of the specimens of L. squarrulosa from Missouri are relatively short plants with relatively few heads. However, at scattered sites, especially in sandy soils of Crowley’s Ridge, populations occur in which the plants are much taller, with elongate, many-headed inflorescences. The relationship between these different growth forms and their intermediates is not presently understood.