Solidago riddellii
Solidago sect. Ptarmicoidei
Riddell's goldenrod
1–10+, erect, glabrous.
basal and proximal cauline usually withering by flowering (other rosettes may be present), tapering to long, winged petioles, blades often recurved, linear- lanceolate or -oblanceolate, 100–240 × 8–16 mm, folded along midrib (V-shaped in cross section), bases usually with (2–)3–8 prominent lateral nerves, apices acute to obtuse, faces glabrous;
mid to distal cauline sessile, blades recurved, linear-lanceolate, 50–70 × 8–11 mm, reduced distally, folded, bases with prominent lateral nerves.
basal (rosettes) usually present at flowering, largest;
petiole bases or vasculature persisting on rhizomes;
proximalmost cauline petiolate, often present but withered at flowering;
proximal and distal usually with 1 prominent nerve (multiple nerves proximally in S. riddellii).
2.8–4 mm, moderately short-hispido-strigose, lanceolate bracteoles 0–1.
narrowly campanulate, 4.5–6 mm.
7–9;
laminae 4.5–5.5 × 0.4–0.5 mm.
6–10;
corollas 4.5–5.2 mm, lobes 0.7–1.8 mm.
(14–18) in 3–4 series, unequal, obtuse, broad, striations weak, obtuse to rounded, glabrous.
striate with 3–7 nerves (except S. ptarmicoides), eglandular.
30–450 in corymbiform to somewhat paniculiform with rounded corymbiform branches (robust plants) arrays, branches and peduncles strigillose.
in flat-topped to rounded corymbiform arrays, sometimes glomerulate.
1.5–2.2 mm, glabrous;
pappi 3.5–4 mm (apically clavate).
bristles in 2 series (outer not clavate, inner longest, somewhat to strongly clavate).
= 18.
Solidago riddellii
Solidago sect. Ptarmicoidei
Species 6 (6 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaves, stems and peduncles moderately to densely short-hairy; distal cauline leaf bladesovate, flat, never folded along midrib | S. rigida |
1. Leaves, stems, and peduncles glabrous or sparsely hairy; distal leaf blades linear to lanceolate, sometimes folded along midrib | → 2 |
2. Rays white (rarely cream); leaf blades linear, stiff, glabrous or sparsely hairy | S. ptarmicoides |
2. Rays yellow; leaf blades linear to linear-lanceolate, stiff or flexible, glabrous | → 3 |
3. Rays 1–4, peduncles usually sparsely to moderately strigillose; Arkansas, Louisiana, Mississippi, Oklahoma, Texas | S. nitida |
3. Rays 6–12, peduncles glabrous or moderately strigillose; Manitoba, midwestern and Great Lakes states s to e Missouri | → 4 |
4. Involucres (5.5–)6–8(–9) mm; proximal and mid cauline leaves usually 3-nerved (sometimes obscurely), the 2 prominent lateral nerves arising proximally and running alongside midnerve for some distance before abruptly diverging; heads usually 10–30(–50)(–100+ rarely, in aberrant plants); plants 30–60+ cm; rays occasionally lighter yellow with age (damp,interdunal hollows, limestone alvars, Michigan, Ontario) | S. houghtonii |
4. Involucres 4–6 mm; mid and distal cauline leaves not 3-nerved or if so then nerves parallel and not abruptly diverging; heads usually (10– on shorter stems)50–400; plants 40–120 cm | → 5 |
5. Leaves flat, only 1 nerve prominent; arrays corymbiform; dunes, marshes, along rivers,Great Lakes area, New York to Illinois and Wisconsin | S. ohioensis |
5. Leaves folded along midrib and with (2–)3–8 prominent nerves at base; arrays somewhat paniculiform with rounded corymbiform branches; moist ground, sw Ontario toWisconsin and se Manitoba, sw to e Missouri | S. riddellii |
IL Wildflowers
MI Flora
MN Wildflowers
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