1. Symphyotrichum anomalum (Engelm. ex Torr. & A. Gray) G.L. Nesom

Aster anomalus Engelm. ex Torr. & A. Gray

Pl. 244 a, b; Map 1013

Plants perennial herbs, usually from a short, stout, somewhat branched rootstock, this sometimes somewhat woody, occasionally also producing elongate rhizomes. Stems 1 to few, 30–100 cm long, unbranched or with few to several ascending branches above the midpoint, relatively uniformly and moderately to densely roughened with short, spreading hairs, sometimes only sparsely so toward the base. Basal and/or lower stem leaves present at flowering, long-petiolate, the petiole sometimes narrowly winged (often only toward the tip), the blade 4–10 cm long, 2.0–5.5 cm wide, heart-shaped, deeply cordate at the base, angled or tapered to a sharply pointed tip, the margins entire or slightly irregular, rarely with a few small teeth, moderately to densely roughened with minute, stiff hairs on the upper surface, densely pubescent with slightly longer (still somewhat sandpapery) hairs on the undersurface, the secondary veins on the leaf undersurface faint or sometimes easily observed, often irregularly fused toward their tips, the veinlets often indistinct, forming a dense, irregular network of relatively short areoles. Median and upper stem leaves progressively smaller, with long to short, often winged but not clasping or sheathing petioles, the blades 1–6 cm long, heart-shaped to narrowly ovate (those along the inflorescence axis mostly lanceolate), cordate to truncate, rounded, or short-tapered at the base, otherwise similar to the lower stem leaves. Inflorescences usually panicles with relatively long, loosely ascending, few-headed, racemose branches, sometimes with denser heads along the branches or reduced to a solitary, open raceme, the heads often appearing relatively long-stalked, the bracts along the ultimate branches 0.6–2.5 cm long, leaflike, linear to narrowly lanceolate, more or less grading into the foliage leaves. Heads mostly 2.0–3.5 cm in diameter (including the extended ray corollas) at flowering. Involucre 5–10 mm long, the bracts in 4–7 unequal, overlapping series. Involucral bracts linear to narrowly lanceolate, relatively long-tapered at the sharply pointed tip, the tip spreading to reflexed, the slender midvein broadened gradually in the apical 1/2–2/3 into a narrowly elliptic or narrowly diamond-shaped, green tip, this also sometimes purplish-tinged, the outer surface sparsely to moderately hairy, the margins moderately to densely hairy, especially toward the tip. Ray florets 20–45 in 1 or 2 series, the corollas well developed, 8–18 mm long, purple to blue, rarely white. Disc florets 20–40, the corollas 4.0–5.5 mm long, the slender portion of the tube shorter than the slightly expanded apical portion, the lobes 0.4–0.6 mm long, 20–25 percent of the total length of the expanded portion. Pappus bristles 3.5–5.0 mm long, off-white to straw-colored or light tan, occasionally purplish-tinged. Fruits 2–3 mm long, mostly with 5 or 6 longitudinal ribs, purplish brown with lighter ribs, glabrous. 2n=16. July–November.

Scattered, mostly in the Ozark and Ozark Border Divisions and the eastern half of the Glaciated Plains (Kansas, Missouri, and Illinois south to Oklahoma and Arkansas). Glades, upland prairies, savannas, mesic to dry upland forests on rocky slopes, and ledges and tops of bluffs; also fencerows and roadsides.

Rare plants with white ray corollas have been called A. anomalus f. albidus Steyerm. The global distribution of the species appears to be restricted mostly to the Ozark Mountains. Although in Missouri S. anomalum is often associated with acidic substrates, in other states the species reportedly grows more commonly at calcareous sites (Gleason and Cronquist, 1991).