13. Solidago nemoralis Aiton (old-field goldenrod, gray goldenrod)
Pl. 243 a, b;
Map 1002
Plants with
branched short- to moderately creeping rhizomes. Stems solitary or more
commonly few to several, 20–100 cm long, erect or ascending, with several fine,
longitudinal ridges or grooves, densely pubescent with minute, mostly curved
hairs 0.1–0.3 mm long, not shiny, not glaucous, the upper nodes sometimes
producing small clusters of leaves in the axils of the main leaves. Leaves
basally disposed and persistent at flowering (additional rosettes usually
present adjacent to the flowering stem). Basal and lowermost stem leaves with
the blade 2–10 cm long, 0.7–2.0 cm wide, mostly 3–8 times as long as wide,
nearly linear to narrowly oblanceolate, oblanceolate, or narrowly obovate,
relatively thin or sometimes somewhat thickened, tapered gradually to a short
to long, winged petiole at the base, rounded or angled to a bluntly or sharply
pointed tip, the margins entire to finely scalloped or bluntly to sharply
toothed, inconspicuously hairy, the surfaces densely pubescent with minute,
mostly curved hairs 0.1–0.3 mm long, the undersurface usually with 1 main vein
(a basal or median pair of secondary veins sometimes slightly more prominent
toward the base than the others), the fine, pinnate secondary veins usually
easily observed (these usually forming an irregular network). Median and upper
stem leaves 0.8–6.0(–8.0) cm long, linear to narrowly oblanceolate or
lanceolate, the margins mostly entire, otherwise similar to the lower stem
leaves. Inflorescences dense, often narrowly pyramidal panicles (broadest near
the base), the longer branches and tip usually somewhat arched or nodding, the
heads oriented upward along the branches. Involucre 3–6 mm long, the bracts in
3–5 unequal series. Involucral bracts oblong-ovate to narrowly
oblong-lanceolate and mostly rounded to bluntly pointed at the
appressed-ascending tip (those of the outer series sometimes sharply pointed),
the thin, white to yellowish white margins hairy (at least toward the tip), the
outer surface glabrous, with a poorly differentiated, green to light green
central region above the midpoint, this tapered gradually to the midvein, the
midvein often slightly thickened and no additional veins present. Receptacle
naked. Ray florets 5–9, the corollas 3.0–5.5 mm long, yellow. Disc florets 3–9,
the corollas 2.5–4.5 mm long, the lobes 0.5–0.9 mm long, yellow. Pappus 2–4 mm
long, a few of the bristles often slightly thickened toward the tip. Fruits 0.5–2.0
mm long, narrowly obovoid, sparsely to moderately finely hairy. 2n=18,
36. July–November.
Scattered nearly
throughout the state (eastern U.S. west to Montana and New Mexico; Canada).
Upland prairies, loess hill prairies, savannas, glades, ledges and tops of
bluffs, openings of mesic to dry upland forests, and occasionally banks of
streams and margins of ponds and fens; also old fields, pastures, railroads,
roadsides, and open, disturbed areas.
Solidago
nemoralis is a
characteristic species of old fields and other open, grass-dominated habitats.
Traditionally, most botanists have divided S. nemoralis into three or
more infraspecific taxa. Brammall and Semple (1990) and Semple et al. (1990)
performed detailed studies of cytological and morphometric variation across the
range of the species, concluding that there were only two elements that could
be separated consistently. These two subspecies are similar to the ones that
Steyermark (1963) recognized as varieties, although Steyermark emphasized
differences in leaf morphology, whereas Semple and his colleagues emphasized
quantitative features of the heads, florets, and fruits that tend to correlate
with ploidy level. Some Missouri specimens are difficult to determine below the
species level, and there is some degree of morphological overlap between the
two subspecies for every feature cited below.