1. Liatris aspera Michx. (rough gayfeather)

L. sphaeroidea Michx.

Pl. 269 f–h; Map 1121

Rootstock a more or less globose to ovoid corm, sometimes appearing somewhat erect and angular or irregular. Stems (30–)50–180 cm long, moderately to densely pubescent with short, curled hairs, sometimes nearly glabrous toward the base. Basal and adjacent lower stem leaves short- to long-petiolate, the blades 6–25 cm long, 4–25 mm wide, oblanceolate to narrowly elliptic (rarely broader), the surfaces glabrous to densely short-hairy, green, with 1 main vein, grading abruptly to the shorter stem leaves, these mostly sessile, 2–10 cm long, narrowly oblanceolate to more commonly linear. Inflorescences elongate spicate racemes, the heads mostly relatively loosely to more densely spaced (the axis usually visible between heads), sessile or with stalks to 8 mm long, these usually with only 1 basal bract. Heads with 14–30 disc florets, the terminal head not noticeably larger than the others. Involucre 9–16 mm long, broadly cup-shaped to broadly bell-shaped, with 4 or 5 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 broad, thin, pale to transparent margins, the margins or entire bracts sometimes strongly purplish-tinged, appearing irregularly torn or strongly uneven (irregularly wavy or scalloped), the main body appearing swollen or pouched toward the tip. Corollas 8–11 mm long, the tube hairy on the inner surface. Pappus bristles barbed. Fruits 4–6 mm long. 2n=20. August–November.

Scattered nearly throughout the state, although apparently absent from most of the Mississippi Lowlands Division (eastern U.S. west to North Dakota and Texas; Canada). Upland prairies, loess hill prairies, glades, exposed ledges and tops of bluffs, savannas, openings of mesic to dry upland forests, and rarely banks of streams; also pastures, railroads, and roadsides.

Rare, white-flowered individuals have been called f. benkei (J.F. Macbr.) Fernald. A putative hybrid with L. squarrosa is known from Barry County, and a possible instance of hybridization with L. squarrulosa has been collected in Texas County. Gaiser (1946) named a putative hybrid between L. aspera and L. pycnostachya from Minnesota as L. ×frostii Gaiser. A single historical collection from Pettis County appears intermediate between these two species. Gaiser had annotated this sheet as L. ×sphaeroidea, which she thought might be a hybrid involving L. aspera and one or more other unknown parents, but that name apparently instead is merely a synonym of L. aspera.