12. Solidago missouriensis Nutt. var. fasciculata Holz. (Missouri goldenrod)

Pl. 242 e, f; Map 1001

Plants with branched, short- to long-creeping rhizomes, often also thickened at the stem bases. Stems 1 to few, 30–100 cm long, erect or ascending, with several fine, longitudinal lines or grooves, glabrous below the inflorescence (sparse, short hairs occasionally present along the inflorescence branches), not shiny, not glaucous, the median and upper nodes usually producing small clusters of leaves in the axils of the main leaves. Leaves basally disposed but often withered or absent at flowering (additional rosettes sometimes present adjacent to the flowering stem). Basal and lowermost stem leaves with the blade 6–15 cm long, 0.5–1.5 cm wide, mostly 7–10 times as long as wide, narrowly oblanceolate, somewhat thickened and stiff, tapered gradually to the winged petiole at the base, angled to a sharply pointed tip, the margins sharply toothed, minutely hairy, the surfaces glabrous, the undersurface with 3 main veins, the lateral pair finer than the midvein, the veinlets usually easily observed, forming an irregular, dense network. Median and upper stem leaves 1–10 cm long, narrowly oblanceolate to narrowly elliptic or nearly linear, sessile or short-petiolate, the margins toothed to entire, all but the uppermost with 3 main veins, otherwise similar to the lower stem leaves. Inflorescences relatively dense, narrow to broad, pyramidal panicles, the longer branches and often also the tip arched or nodding, the heads oriented upward along the branches. Involucre 2.5–4.5 mm long, the bracts in 3 or 4 unequal series. Involucral bracts oblong-ovate to narrowly lanceolate and rounded or bluntly pointed (those of the outer series often sharply pointed) at the appressed-ascending tip, the margin sparsely hairy toward the tip, the outer surface glabrous, usually entirely yellowish but occasionally with a poorly differentiated, greenish yellow central region above the midpoint, the midvein somewhat thickened and keeled, and no additional veins present. Receptacle frequently with a few slender, chaffy bracts (similar to the involucral bracts but usually somewhat shorter) toward the margin. Ray florets 7–13, the corollas 2–3 mm long, yellow. Disc florets 6–15, the corollas 2.5–4.0 mm long, the lobes 0.5–0.9 mm long, yellow. Pappus 2.5–3.0 mm long, some of the bristles slightly thickened toward the tip. Fruits 1.0–2.2 mm long, obovoid, glabrous or finely hairy. 2n=18, 36. July–October.

Scattered nearly throughout the state, but uncommon in the eastern portion of the Ozark Division and the Mississippi Lowlands (Michigan to Tennessee west to Washington and Arizona; Canada). Upland prairies, loess hill prairies, glades, savannas, and rarely openings and margins of mesic to dry upland forests; also old fields, railroads, and roadsides.

This species superficially resembles S. gattingeri but usually is fairly easily distinguished by the key characters. The infraspecific taxonomy is complex and requires further study. Steyermark (1963) treated two varieties as occurring in Missouri: var. fasciculata Holz., with broader inflorescences and shorter, less hairy fruits, and var. missouriensis, with narrower inflorescences and slightly longer, hairier fruits. Cronquist (1955) reevaluated the complex, recognizing a widespread tall-stemmed, relatively leafy var. fasciculata and three shorter-stemmed, less leafy varieties endemic to the northwestern United States differing from each other in details of head size and inflorescence morphology. His treatment has been adopted in several later works (Cronquist, 1980; Barkley, 1986; Gleason and Cronquist, 1991; Semple et al., 1999) and excludes Missouri from the range of var. missouriensis. Semple et al. (1999) noted that tetraploid plants (2n=36) are known only from the western portion of the species range, but relatively few chromosome counts exist to date for the species. In the northwestern United states, there apparently is some morphological intergradation between plants attributed to var. fasciculata and var. missouriensis.