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Key to Solidago

Asteraceae

Solidago

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(c) Bradley, Keith
1 Leaves primarily cauline, the basal leaves absent or withering early (if present, smaller than the lower and middle stem leaves), with the lower part of the stem usually naked or nearly so by the time of flowering.
(c) Witsell, Theo - CC-BY-NC, permission granted to NCBG
  2 Heads borne in cylindrical and thyrsoid arrays, the central axis being the upper stem, the lateral branches of the array of similar length to one another and subtended by either well-developed leaves (longer than the branch) or smaller bracts (shorter than the branch).
(c) Ward, Scott G - CC-BY
(c) Ward, Scott G - CC-BY
(c) Pogacnik, Shaun - CC-BY-NC, permission granted to NCBG
    3 Leaves entire or obscurely few-toothed; achenes glabrous at maturity; outer phyllaries with squarrose tips (tips appressed in S. rigidiuscula); [subgenus Solidago, section Thyrsiflorae and section Erecta (in small part)].
(c) Bradley, Keith
(c) Bradley, Keith
  2 Heads borne in paniculiform arrays (with longer lateral branches towards the middle or the base of the array, the heads on at least the longer branches secund).
(c) Ward, Scott G
      4 Leaves with only the midvein readily apparent; leaves entire; leaf surfaces finely translucent punctate (most obviously seen with transmitted light or with 10× magnification); fresh leaves usually anise-scented; [subgenus Triactis, section Odorae].
(c) Marcum, Paul
      4 Leaves either triple-veined or pinnately-veined; leaves entire or often at least obscurely toothed; leaf surfaces not translucent punctate; fresh leaves not anise-scented.
(c) Pippen, Jeffrey S.
(c) Fleming, Gary P.
        5 Leaves pinnately veined; leaves mostly 1-5× as long as wide; [subgenus Pleiactila, section Venosae].
(c) Sorrie, Bruce A. - CC-BY
(c) Fleming, Gary P.
        5 Leaves triple-veined (two side veins arising near the base of the leaf and arching first away from and then back towards the midvein); leaves 2-20× as long as wide; [subgenus Pleiactila, section Unilaterales].
(c) Julie, Tuttle
(c) Powell, Eric M - CC-BY-NC, permission granted to NCBG
1 Leaves basally disposed, the basal leaves usually the longest leaves on the plant, often longer-petioled than the stem leaves, the stem leaves often graduating smaller upwards on the stem, though sometimes nearly even in size from lower stem to upper stem leaves.
(c) Ward, Scott G
(c) Ulrey, Christoper
          6 Heads borne in corymbiform arrays, flat-topped or broadly rounded; array of heads about as broad as long, or broader.
(c) Ulrey, Christoper
             7 Larger leaves obovate, 5-10 cm long, 1.5-4 cm wide, with prominent teeth; plants small, 0.5-4 dm tall; [high elevation rock outcrops on Grandfather Mountain, Roan Mountain, and Hanging Rock Mountain (Avery, Watauga, and Mitchell counties, NC, and Carter County, TN)]; [subgenus Pleiactila, section Multiradiatae]
(c) Ward, Scott G
(c) Oldham, Michael J. - CC-BY-NC, permission granted to NCBG
             7 Larger leaves elliptic-oblong, linear, or lanceolate, 6-25 cm long, 0.1-10 cm wide, with small, obscure teeth; plants more robust, 4-15 dm tall; [of low elevations]; [subgenus Pleiactila, section Ptarmicoidei]
          6 Heads either borne in 1-several thyrsiform (cylindrical) arrays (the heads on short lateral axes about even in length from top to bottom of the array, the heads not secund), or in paniculiform arrays (with longer lateral branches towards the middle or the base of the array, the heads on at least the longer branches secund); array of heads usually much or at least somewhat longer than broad.
(c) Ward, Scott G
               8 Petioles of the lower stem leaves sheathing the stem (appressed to it and curving around one side of it); leaves basally disposed, the leaves up the stem very many in most species, ascending or appressed, sometimes fewer and more widely spaced; inflorescence either narrowly cylindrical or with well-developed branches with heads secundly arrayed; plants of permanently or seasonally saturated wetlands (bogs, fens, seeps, wet pinelands, marsh edges), or of maritime habitats, or less typically of xerohydric acid flatwoods; [subgenus Pleiactila, section Maritimae].
(c) Fleming, Gary P.
               8 Petioles of the lower stem leaves sessile (not sheathing, but auriculate-clasping at a ca. 90 degree angle to the stem in S. auriculata); leaves basally disposed, the leaves up the stem not very many and with short internodes in most species; inflorescence cylindric or paniculiform; plants of uplands, bottomlands, and sometimes seasonally saturated wetlands (bogs and fens).
(c) Ward, Scott G
                 9 Heads borne in a cylindrical and thyrsoid array, the central axis being the upper stem, the lateral branches of the array of similar length to one another and subtended by either well-developed leaves (longer than the branch) or smaller bracts (shorter than the branch).
© Scott Ward
                   10 Basal and lower stem leaves with blades truncate to cordate to a winged petiole; heads discoid (lacking ray flowers); [GA and FL Panhandle west through AL and MS to w. LA]; [subgenus Solidago, section Brintonia]
(c) Ward, Scott G
                   10 Basal and lower stem leaves sessile, or with blades cuneate to the petiole; heads radiate (with 1-16 disc flowers); [collectively widespread].
(c) Pippen, Jeffrey S.
                     11 Heads very large, involucre 8-13 mm high; fresh leaves noticeably thick and rubbery in texture; [subgenus Pleiactila; subsection Glomeruliflorae]; [high elevations of NC and TN]
(c) Littlefield, Tara Rose - CC-BY-NC, permission granted to NCBG
                     11 Heads smaller, involucre < 8 mm high (or 6-12 mm high in Solidago arenicola); fresh leaves not thick or rubbery in texture; [collectively widespread].
(c) Fleming, Gary P.
                       12 Phyllaries and vegetative parts lacking minute sticky glands; stem leaves sessile.
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Key to Solidago, Key A: Key to "thyrsiflorous goldenrods" -- with stem leaves dominant and cylindrical inflorescences [subgenus Solidago, sections Thyrsiflorae (mostly) and an Erectae]

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1 Outer phyllaries appressed; [subgenus Solidago; section Erectae]
1 Outer phyllaries with squarrose tips; [subgenus Solidago; section Thyrsiflorae].
  2 Leaves oblanceolate-obovate, often short acuminate at the apex; mid-stem leaves 8-14 cm long, 18-40 mm wide, the margins sharply serrate on at least the upper 2/3
  2 Leaves narrowly to broadly elliptic (or less commonly slightly oblanceolate), acute at the apex; mid-stem leaves 3-8 (-10) cm long, 8-25 mm wide, margins entire to shallowly serrate on only the upper ½ to 2/3.
    3 Middle and inner series phyllaries glabrous, usually minutely glandular or resinous and shiny; mid and upper stem leaves usually narrowly lanceolate, rarely broadly lanceolate to ovate, green to shiny silvery; [MO to LA west to e. KS to se. and c. TX, disjunct in n. COA]
    3 Middle and inner series phyllaries sparsely to moderately strigose, sometimes minutely glandular; mid and upper stem leaves lanceolate-elliptic to ovate-elliptic; [NC to n. FL west to AL; e. KS, e. OK, c. TX westwards]
      4 Involucres at anthesis (6-) avg. 7.5 (-8) mm high; [NC to n. FL west to AL, disjunct in e. TX]
      4 Involucres at anthesis (4.3-) avg. 5.3 (-7) mm high; [e. KS, e. OK, c. TX westwards]
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Key to Solidago, Key B: Key to "axillary forest goldenrods" -- with stem leaves dominant (mostly) and heads axillary to well-developed leaves
[subgenus Pleiactila, section Glomeruliflorae

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(c) Shaw, Joey
1 Leaves typically basally disposed, but if flowering stems with leaves primarily cauline, plants clonal with many stemless basal rosettes; involucres 10-11 mm high
(c) Oldham, Michael J. - CC-BY-NC, permission granted to NCBG
1 Leaves primarily cauline; involucres 3.5-9 mm high.
(c) Hartley, Nate - CC-BY-NC, permission granted to NCBG
  2 Stem terete, glaucous.
    3 Lower midstem leaves narrowly lanceolate, 5-15 cm long, 0.8-3 cm wide, 5-6× as long as wide; stems strongly arching; plants growing singly; [widespread in our area]
    3 Lower midstem leaves broadly lanceolate to rhombic, 5-9 cm long, 1.3-2.4 cm wide, 3-4× as long as wide; stems weakly arching; plants usually strongly clonal, forming relatively dense patches; [Coastal Plain, NC to FL, west to LA and AR]
  2 Stem striate-angled, green.
      4 Larger leaf blades on a plant 2-6 cm long; stems densely villous with spreading white hairs; [endemic to sandstone rockhouses in the Red River Gorge in Menifee, Powell, and Wolfe counties, KY]
      4 Larger leaf blades on a plant 8-20 cm long; stems glabrous or sparsely to moderately hairy, the hairs neither long nor white; [of various dry and mesic habitats, collectively widespread in our area].
        5 Leaves 1-3 (-3.5)× as long as wide.
          6 Leaves 1-2.2 (-2.5)× as long as wide, abruptly contracted to a winged petiole; teeth of the leaf margins elongate and narrow, acuminate, mostly (2-) 3-8 mm long (as measured on the upper side of the tooth)
          6 Leaves (2.2-) 2.5-3 (-3.5)× as long as wide, cuneate to a sessile base; teeth of the leaf margins not notably elongate and narrow, mostly 1-2 (-3) mm long (as measured on the upper side of the tooth), but sometimes longer and more like S. flexicaulis
             7 Achenes sparsely to moderately strigose; ray flowers 2-4 (-6); [Appalachian, east of the Mississippi River]
        5 Leaves 3-10× as long as wide.
(c) brettaugust - CC-BY
               8 Plants solitary; involucres (5-) 5.6-7 (-8) mm high, eglandular; phyllaries 0.7-1 mm wide, usually 1-nerved; stems 4-9 (-10) dm tall; ray flowers 2-4 (-6); [broadly Appalachian]
(c) Fleming, Gary P.
               8 Forming dense, clonal colonies from thick, creeping rhizomes; involucres 6.4-8.5 (-9) mm high, glandular pubescent; phyllaries 1-1.5 mm wide, usually 3-10-nerved; stems (2-) 7-16 dm tall; ray flowers 5-8; [apparently restricted to high elevations in the Blue Ridge of w. NC, e. TN, and sw. VA]
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Key to Solidago, Key C: Key to "licorice goldenrods" -- with stem leaves dominant and heads in paniculiform arrays, the leaves translucent dotted and entire [subgenus Triactis; section Odorae]

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1 Main leaves ovate to lanceolate, 2-5 (-6)× as long as wide; stem pubescence general and circumferential; [of FL]
1 Main leaves lanceolate to linear, (4-) 5-15× as long as wide; stem pubescence in lines decurrent down the stem from the margins of the leaf bases; [widespread]
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Key to Solidago, Key D: Key to "rugosa goldenrods" -- with pinnately-veined stem leaves dominant and well-developed paniculiform inflorescences [subgenus Pleiactila; section Venosae]

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1 Larger leaves 1-2× as long as wide, 2-7 cm wide; [IL & MO south to AR]; [subgenus Pleiactila, section Venosae, subsection Drummondiani]
1 Larger leaves 2-5+× as long as wide, 0.6-4 cm wide; [collectively widespread]
  2 Leaf venation not notably reticulate; plants to 12 dm tall, from a compact caudex; [subgenus Pleiactila, section Venosae, subsection Ulmifoliae].
    3 Leaves sparsely hirsute below, at least on the midvein and larger lateral veins
      4 Midstems densely pubescent; midstem leaves with attenuate to rounded bases; midvein of phyllaries as wide or wider than the tissue on each side (midveins of phyllaries equal or greater than 1/3 the phyllary width; [mainly Interior Highlands of AR and MO, rarely disjunct eastwards]
      4 Midstems glabrous to sparsely pubescent; midstem leaves acuminate; midvein of phyllaries narrower than the tissue on each side (midveins of phyllaries 1/3 to 1/5 the phyllary width); [widespread in our region]
  2 Leaves pinnately veined and also forming a prominent reticulum, the veins (primary, secondary, and tertiary) very evidently raised on the undersurface (less obviously so in S. fistulosa); plants to 30 (-40) dm tall, from long-creeping rhizomes, thus forming clonal patches; [subgenus Pleiactila, section Venosae, subsection Venosae].
        5 Mid-stem leaves sessile, somewhat clasping; leaf margins nearly entire to obscurely serrulate; leaves planar
        5 Mid-stem leaves subsessile, not clasping; leaf margins strongly serrate; leaves rugose.
          6 Involucres 4-6 mm high; broader phyllaries 0.7-1.2 mm wide; stems glabrous below the inflorescence; mid-stem leaves elliptic (widest near the middle)
          6 Involucres (2-) 2.5-3.5 (4.5) mm high; phyllaries mostly < 0.5 mm wide; stems hairy or glabrous below the inflorescence; mid-stem leaves lanceolate to ovate (widest below the middle).
             7 Leaves relatively thin, not very rugose, usually sharply serrate, the apices acuminate, glabrous or soft-hairy on the surfaces; rays (4-) 5-12 (-13).
               8 Stem glabrous throughout (except for scattered hairs in inflorescence), stem with striate ridges decurrent from leaf bases; leaf blades appressed serrate (teeth short), blades glabrous beneath except for sparse, short, appressed, straight hairs; early blooming (1 month earlier than S. rugosa in same area); [permanently saturated, ± forested wetlands with Sphagnum moss, such as red maple-Atlantic white cedar swamps, streamhead pocosins, montane bogs]
               8 Stem pubescent with crinkly hairs throughout (occasional plants varying to glabrate below), stem without striate ridges decurrent from leaf bases; leaf blades sharply serrate (teeth coarse), blades villous to crinkly hairy beneath; late blooming (ca. 1 month later than S. aestivalis in same area); [dry to moist fields, meadows, and other open habitats]
             7 Leaves relatively thick and firm, strongly rugose, usually subentire to bluntly serrate, the apices often only acute, slightly to strongly scabrous or stiffly-hairy on the surfaces; rays 4-9.
                 9 Inflorescences narrow, the lower lateral branches only slightly exceeding the subtending leaves; leaves sparsely pubescent; [of the Southern Appalachians]
                 9 Inflorescences broad, the lower lateral branches generally much longer than the subtending leaves; leaves moderately to densely pubescent; [collectively widespread].
                   10 Upper stem leaves lanceolate to elliptic, not much reduced relative to leaves lower on the stem
                   10 Upper stem leaves ovate, much reduced relative to leaves lower on the stem
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Key to Solidago, Key E: Key to "tall goldenrods" -- with 3-veined stem leaves dominant and secund paniculiform inflorescences [subgenus Pleiactila; section Unilaterales (in part)]

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1 Upper stem (above the midpoint, up to the branches of the inflorescence) glabrous.
  2 Plants to 20 dm tall; basal leaves never present; mid-stem leaves averaging 4-6× as long as wide; upper stem usually slightly to moderately glaucous as well as glabrous; [widespread]; [subgenus Pleiactilis, section Unilaterales, subsection Serotinae]
  2 Plants to 10 dm tall; basal leaves withering or not before flowering (if not, also keyed elsewhere), often with associated sterile offshoots with basal leaves; mid-stem leaves averaging 5-10× as long as wide; upper stem glabrous, green; [KY, TN, and MS westwards].
    3 Rootstock short and branched, not producing creeping rhizomes; ray flowers 5-8; receptacle lacking intercalated green bracts (resembling phyllaries) inward from the rays; mid and upper stem leaves usually lacking axillary fascicles of smaller leaves; [subgenus Pleiactilis, section Unilaterales, subsection Radulae]
    3 Rootstock producing creeping rhizomes; ray flowers 7-13; receptacle often with a few intercalated green bracts (resembling phyllaries) inward from the rays; mid and upper stem leaves usually with axillary fascicles of smaller leaves; [subgenus Pleiactilis, section Unilaterales, subsection Junceae]
1 Upper stem hairy (above the midpoint, up to the branches of the inflorescence), variously puberulent, strigillose to strigose, villous, or scabrous.
      4 Midstem leaf blades 1-4 (-5)× as long as wide, the base attenuated to a winged petiole (at least in leaves of the lower midstem(; plants 1-10 dm tall; [collectively in IL, MO, AR, and LA westwards, disjunct eastwards in KY, NC, SC, GA, and AL]
        5 Leaf margins coarsely serrate; midstem leaf blades mostly 1.3-2× as long as wide; leaf surfaces evenly short villous; [IL & MO south to AR]; [subgenus Pleiactilis, section Venosae, subsection Drummondiani]
        5 Leaf margins entire to finely serrate; midstem leaf blades mostly 2-4 (-5)× as long as wide; leaf surface vestiture appressed to scabrous; [subgenus Pleiactilis, section Unilaterales, subsection Radulae].
          6 Leaf surfaces with appressed (strigillose) hairs; upper stem vestiture densely strigose, the stems appearing grayish-green; rhizomes long-creeping, the plants forming clonal patches; [OK and nc. TX westwards and northwestwards]
          6 Leaf surfaces scabrous; upper stem vestiture scabrous to loosely puberulent, the stems appearing green or dingy green; rhizomes short (less commonly moderately creeping); [se. KS, OK, and TX eastwards]
      4 Midstem leaf blades 4-20× as long as wide, the base sessile and cuneate to rounded; plants 3-20 dm tall; [collectively widespread].
             7 Rays 2-8; midstem leaves 4-15 mm wide, mostly 6-20× as long as wide, either twisted at base or not.
               8 Larger mid-stem leaves lanceolate to narrowly elliptic, 7-10 cm long, 10-15 mm wide; leaves not twisted; [KY and s. IN]; [subgenus Pleiactilis, section Unilaterales, subsection Canadensae]
               8 Larger mid-stem leaves linear to lance-linear, 2-9 cm wide, 2-7 (-10) mm wide; leaves either twisted at base or not; [either OK and westwards, or Coastal Plain from VA to FL west to TX and AR].
                 9 Leaves 4-9 cm long, 4-5 mm wide; [inland provinces, OK and westwards]; [subgenus Pleiactilis, section Unilaterales, subsection Radulae]
                 9 Leaves 2-7 cm long, 2-7 (-10) mm wide; [Coastal Plain, VA to FL west to TX and AR]; [subgenus Pleiactilis, section Unilaterales, subsection Tortifoliae]
             7 Rays 4-17 (-24); midstem leaves 5-30 mm wide, 4-12× as long as wide, not twisted at base.
                   10 Midstem leaves mostly 8-12× as long as wide.
                     11 Rays 10-15; [wet pine savanna and marsh habitats, Coastal Plain of NC, SC, GA, FL, AL, and MS]; [subgenus Pleiactilis, section Unilaterales, subsection Tortifoliae]
                     11 Rays 7-11; [riverscour habitats, inland provinces of PA, MD, DC, VA, WV, IN, KY, TN]; [subgenus Pleiactilis, section Unilaterales, subsection Canadensae]
                   10 Midstem leaves mostly 4-6× as long as wide; [subgenus Pleiactilis, section Unilaterales, subsection Canadensae].
(c) McClosky, Daniel - CC-BY
                       12 Mid-stem leaves serrate, the teeth 3-8 (-10) per side, the largest > 1.5 mm long; involucres 1.7-2.5 (-3.0) mm high.
                       12 Mid-stem leaves entire to serrulate, the teeth usually 0-6 per side (up to 14); involucres (2.5-) 3-4.5 mm high.
                            14 Stem densely and closely villous-tomentose; leaves densely and evenly short pilose above and beneath; [western]
                            14 Stem short pilose to puberulent; leaves usually noticeably less hairy above than beneath and often darker colored above, with ascending-appressed hairs on the upper surfaces; [collectively widespread].
                              15 Upper surface of the leaves moderately to densely pubescent with short, curved to spreading hairs; [western]
                              15 Upper surface of the leaves sparsely to moderately roughened with minute bulbous-based hairs (stouter and shorter than the hairs on the lower surface), or glabrous except along the veins; [collectively widespread].
                                16 Inflorescence broad; upper stem leaves not reduced in size relative to the mid-stem leaves; [broadly eastern]
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Key to Solidago, Key F: Key to "dwarf alpine goldenrods" -- dwarf plants with rounded corymbs [subgenus Pleiactila, section Multiradiatae]

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1 One species
1 One species
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Key to Solidago, Key G: Key to "ptarmicoid goldenrods" -- with corymbs [subgenus Pleiactila, section Ptarmicoidei]

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1 Rays white; leaves linear-lanceolate to linear-oblanceolate, the longer (10-) 15-20× as long as wide; pappus bristles slightly to strongly clavellate-thickened;
1 Rays yellow; leaves oblong, elliptic, obovate, or spatulate, 2-8× as long as wide; pappus bristles not clavellate thickened.
  2 Leaves of the midstem 1-7 mm wide, 10-20× as long as wide; ray flowers 1-4/head, disk flowers 7-13/head; [AR, OK, MS, LA, and TX]
  2 Leaves of the midstem 8-20 mm wide, 2-12× as long as wide; ray flowers 6-14/head; disk flowers 6-35/head; [collectively widespread].
    3 Leaves of the midstem 8-12 mm wide, 4-12× as long as wide; leaf surfaces, stems, and peduncles glabrous; [marshes, swamps, moist to wet prairies, of OH, IN, OL, MO, and AR (allegedly disjunct in nw. GA and e. VA].
      4 Leaves essentially planar, with only the midvein prominent; leaves straight to slightly curved, appressed to ascending
      4 Leaves folded along the midvein (conduplicate, V-shaped in ×-section), with 3-7 veins prominent from the base of the blade; stem leaves strongly recurved away from the stem
    3 Leaves of the midstem 12-20 mm wide, 2-3.5× as long as wide; leaf surfaces, stems, and peduncles glabrescent to densely pubescent; dry to moist prairies, glades, and savannas].
        5 Outer series of phyllaries glabrous on the back (glabrous to short-ciliate on the margin); leaf undersurface glabrous to somewhat hispid (0-20 hairs per square mm) (the margins and midrib beneath often more densely pubescent); stems glabrous to somewhat hispid (0-25 hairs per square mm)
        5 Outer series of phyllaries pubescent on the back (short-ciliate on the margin); leaf undersurface hispid (7-50 hairs per square mm); stems slightly to strongly hispid (10-70 hairs per square mm).
          6 Pubescence of the stems and leaf surfaces finely and densely hispid-strigose, > 50 hairs per square mm; plants usually 3-7 dm tall; flowering arrays compact; inner phyllaries linear, conspicuously strigillose
          6 Pubescence of the stems and leaf surfaces coarsely hispid, < 50 hairs per square mm; plants 6-15 dm tall; flowering arrays loose, more diffuse; inner phyllaries oblong and with a rounded apex, glabrate or sparsely strigillose
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Key to Solidago, Key H: Key to "bog wand goldenrods" -- with narrowly cylindrical (sometimes broader) inflorescences and sheathing petiole bases [subgenus Pleiactila, section Maritimae]

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1 Leaves somewhat fleshy, the stem leaves reduced but not very markedly so; inflorescence almost always with lower branches strongly recurved with secund heads; [usually of maritime or otherwise saline habitats, rarely in nontidal marshes or swamps].
  2 Involucres 3-4 mm high; rays 7-11; disc flowers ca. 10-16; leaf margins ciliolate; larger leaves < 3 cm wide; [MA south to FL, west to TX and beyond]
  2 Involucres 4-7 mm high; rays 12-17; disc flowers ca. 17-22; leaf margins not ciliolate; larger leaves > 3 cm wide; [VA northward]
1 Leaves not fleshy (rarely so in S. stricta of near coastal situations), the stem leaves much reduced relative to the basal; inflorescence showing only relatively weak tendency to recurved branches with secund heads; [inland habitats, except rarely S. stricta].
    3 Basal leaves 0.7-8 cm wide; plants short, 4-10 (-15) dm tall, typically fairly stout; [mainly of the Mountains (and the Coastal Plain from e. VA northwards), e. VA, w. NC, nw. SC, ne. GA, and northward].
      4 Ray flowers averaging 3; disc flowers averaging 8; heads 6-7 mm tall; [seepage over sloping rock on granitic domes, of sw. NC, nw. SC, and ne. GA]
      4 Ray flowers averaging 5; disc flowers averaging 6; heads 4-5 mm tall; [peaty bogs and fens, w. NC and e. TN northward].
        5 Basal leaves 0.7-2.5 cm wide; stem leaves linear or lanceolate (the lower cauline leaves 0.7-3 cm wide); disc flowers 9-15; [PA and WV (?) northwards]
        5 Basal leaves 3-8 cm wide; stem leaves oblong-lanceolate (the lower cauline leaves 3-8 cm wide); disc flowers 4-8; [scattered in NC and TN; less sparsely distributed northwards]
    3 Basal leaves 0.2-2.5 (-5) cm wide; plants short to tall, 3-20 dm tall, typically very slender; [Coastal Plain and lower Piedmont and southward].
          6 Basal leaves 0.2-0.5 (-0.7) cm wide; [s. peninsular FL]
          6 Basal leaves 0.7-2.5 (-5) cm wide; [collectively more widespread].
             7 Mid stem leaves mostly linear, > 7 × as long as wide (types: 7.5-12.5); lower floral branches often remote, distally recurved, and elongate, as much as 30 cm long (but not always present); [e. NC south to c. Panhandle FL, west to s. AL]
             7 Mid stem leaves mostly elliptic, oblanceolate, or lanceolate, < 7 × as long as wide; lower floral branches shorter, not remote (to 20 cm and virgate in S. stricta).
               8 Basal blades 1.5-5 cm wide, margins serrate to crenate, reticulum coarse and conspicuous; [Coastal Plain, s. NJ to e. NC]
                 9 Leaf margins smooth, entire; ray flowers 8-13 per head; disk flowers 14-25 per head; pappus (2.5-) 3.0-3.5 mm long; [se. NC and adjacent ne. SC]
                 9 At least basal leaves scabrous-margined, often minutely to noticeably denticulate; ray flowers 2-7 per head; disk flowers 6-16 per head; pappus 1.5-5.1 mm long; [collectively more widespread].
                   10 Fruiting heads 8-11 mm long; disk corollas 4.3-5.5 mm long; pappus 4.2-5.1 mm long; [NC south to s. FL, west to e. LA]
                   10 Fruiting heads 3.9-8 mm long; disk corolla 2.5-5 mm long; pappus 1.5-4.4 mm long.
                     11 Lower floral branches often recurved and/or spreading; fruiting heads 3.9-6.5 mm long; involucre 2.5-4.2 mm long; disk corolla 1.5-3.9 mm long; pappus 1.5-3.0 mm long; [mainly inland provinces, NC west to AL, north to TN and KY]
                     11 Lower floral branches erect to ascending (rarely spreading-recurved); fruiting heads 4-8 mm long; involucre 3.0-6.5 mm long; disk corolla 2.5-5 mm long; pappus 2.3-4.4 mm long; [se. NC]
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Key to Solidago, Key I: Key to a diversity of goldenrods with basally disposed leaves and paniculiform inflorescences with heads secund on the branches
[subgenus Nemorales; and subgenus Pleiactila, sections Argutae, Venosae, Maritimae, and Unilaterales)]

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1 Basal and lower stem leaves petiolate with a cordate or subcordate blade and/or a cordate-clasping petiole; [subsection Argutae].
  2 Pappus > ½× as long as the disc corollas; rays 1-3
  2 Pappus < ¼× as long as the disc corollas; rays 3-6
1 Basal and lower stem leaves with cuneate leaf blades and petioles not cordate-clasping (though leaves may have petioles which sheath the stem).
    3 Blades of lower leaves ovate to elliptic to oblanceolate, their bases truncate, abruptly tapering, or gradually tapering to petiole; lower leaves including petioles mostly less than 4× as long as wide (sometimes longer in S. brachyphylla with densely puberulent leaf surfaces and stems, and in S. boottii and S. tarda with blades sharply serrate and heads lacking phyllary-like bracts interior to ray florets); [subsection Argutae].
      4 Leaves either definitely scabrous or moderately to densely soft-villous or puberulent.
        5 Leaves scabrous on the upper surface.
          6 Involucre (2.5-) avg. 3.9 (-6.5) mm high; basal and lower stem leaves 8-30 cm long, 4-10 cm wide, mostly 2-3× as long as wide; upper stem leaves few, somewhat reduced; disc florets averaging 11.8 per head; [Mountains, Interior Low Plateau, rarely Piedmont, and Coastal Plain only from DE northwards]
          6 Involucre (3.5-) avg. 6.1 (-8.8) mm high; basal and lower stem leaves 6-24 cm long, 2-6 cm wide, mostly 3-5× as long as wide; upper stem leaves many, strongly reduced; disc florets averaging 9.3 per head; [Coastal Plain and very rarely lower Piedmont and AL Mountains]
        5 Leaves moderately to densely soft-villous or puberulent.
             7 Leaves soft-villous; rays 7-12; flowering May-Jun; [Coastal Plain of e. NC and e. SC]
             7 Leaves puberulent; rays 0 (-2); flowering Sep-Nov; [SC (NC?) south to FL and AL]
      4 Leaves either glabrous (or nearly so) or strigose or strigillose.
                 9 Plants with slender, stoloniferous rhizomes (in addition to the main, more deeply-seated rhizomes)
                   10 Upper stem leaves quickly reduced in size compared to the lower, ascending or appressed; basal and lower stem leaves elliptic to obovate (rarely ovate), acute or obtuse, with narrowly attenuate bases; [LA, TX, AR, and OK]
                   10 Upper stem leaves gradually reduced in size, ascending to spreading; basal and lower stem leaves mostly ovate, acute to acuminate, with truncate to obtuse bases; [NJ south to AL]
                       12 Basal leaves cuneate to rounded at the base; leaves of normal herbaceous texture.
    3 Blades of lower leaves oblanceolate to narrowly ovate, gradually tapering to petiole; lower leaves including petioles mostly more than 4× as long as wide (sometimes shorter in S. juncea with at least a few phyllary-like bracts interior to ray florets).
                              15 Petiole bases of basal and lower stem leaves not clasping or sheathing the stem; [of mesic or dry habitats].
                                16 Stems obviously densely and loosely puberulent; [subsection Nemorales]
                                  17 Pappus bristles usually exceeding the length of the ray floret corolla tubes; basal and lower stem leaves narrowly oblanceolate to nearly linear; leaf margins entire or with minute teeth only near the tip; disc corolla lobes (0.6-) 0.8-1.5 mm long; achenes moderately hairy; [mainly western in our region]
                                  17 Pappus bristles usually not (or barely) exceeding the length of the ray floret corolla tubes; basal and lower stem leaves oblanceolate to narrowly obovate; leaf margins crenate-serrate through half or more of their length; disc corolla lobes 0.5-0.9 (-1.0) mm long; achenes sparsely hairy; [widespread in our region]
                                    18 Rhizomes thick, short; stem leaves not 3-nerved; [collectively of various habitats].
                                         20 Upper stem leaves spreading or reflexed, with axillary fascicles of reduced leaves; [east of the Blue Ridge]
                              15 Petiole bases of basal and lower stem leaves sheathing the stem; [seasonally saturated habitats]; [subsection Maritimae].
                                           21 Leaves somewhat fleshy, the stem leaves reduced but not very markedly so; inflorescence almost always with lower branches strongly recurved with secund heads; [usually of maritime or otherwise saline habitats, rarely in nontidal marshes or swamps].
                                             22 Involucres 3-4 mm high; rays 7-11; disc flowers ca. 10-16; leaf margins ciliolate; larger leaves < 3 cm wide; [MA south to FL, west to TX and beyond]
                                           21 Leaves not fleshy (rarely so in S. stricta of near coastal situations), the stem leaves much reduced relative to the basal; inflorescence showing only relatively weak tendency to recurved branches with secund heads; [inland habitats, except rarely S. stricta].
                                               23 Ray flowers averaging 3; disc flowers averaging 8; heads 6-7 mm tall; [seepage over sloping rock on granitic domes, of sw. NC, nw. SC, and ne. GA]
                                               23 Ray flowers averaging 5; disc flowers averaging 6; heads 4-5 mm tall; [peaty bogs and fens, w. NC and e. TN northward].
                                                 24 Basal leaves 0.7-2.5 cm wide; stem leaves linear or lanceolate (the lower cauline leaves 0.7-3 cm wide); disc flowers 9-15; [PA and WV (?) northwards]
                                                 24 Basal leaves 3-8 cm wide; stem leaves oblong-lanceolate (the lower cauline leaves 3-8 cm wide); disc flowers 4-8; [scattered in NC and TN; less sparsely distributed northwards]
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Key to Solidago, Key J: Key to " 'false' goldenrods with no ray flowers [subgenus Solidago, section Brintonia]

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1 One species; [subgenus Solidago, section Brintonia]
1 One species; [subgenus Solidago, section Brintonia]
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Key to Solidago, Key K: Key to "bigheaded goldenrods" [subgenus Pleiactila, section Glomeruliflorae (in part)]

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1 One species; [subgenus Pleiactila; section Glomeruliflorae (in part)]
1 One species; [subgenus Pleiactila; section Glomeruliflorae (in part)]
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Key to Solidago, Key L: Key to "sticky goldenrods" -- with basally disposed leaves and elongate, cylindrical inflorescences, mainly of riverscour habitats [subgenus Solidago, section Erectae (in part)]

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1 Leaves, peduncles, and phyllaries copiously glandular; [Coastal Plain sandhills]
1 Leaves, peduncles, and phyllaries slightly glandular; [rocky glades, cliffs, barrens, and river-scoured outcrops, primarily on mafic or calcareous rocks].
  2 Cypselas pubescent (even when mature) [e. TN and w. VA northward]
    3 Lower stem leaves 7-15× as long as wide, (2.5-) 4.6-9.4 (-11.2) cm long, (2-) 3-9 (-17) mm wide, generally obscurely toothed; [rocky, flood-scoured riversides, from e. KY, e. TN, and n. VA northward]
    3 Lower stem leaves 3-8× as long as wide, (4.2-) 6.2-11.3 (-15.9) cm long, (5-) 10-22 (-31) mm wide, generally sharply toothed; [cliffs and barrens, primarily over mafic rocks, from w. VA northward]
  2 Cypselas glabrous (even when young); [either rocky, flood-scoured riversides of n. AL, nw. GA, sc. NC , e. TN, and e. KY, or habitat uncertain, Piedmont of SC].
      4 Involucres 5-12 mm high; inflorescence with heads more loosely arrayed, with 1-6 heads on a typical 3 cm lateral branch; [n. AL, nw. GA, , e. TN, e. KY, wc. SC]
        5 Heads 6-12 mm high; flowering Sep-Oct; [river scour habitats, n. AL, nw. GA, , e. TN, and e. KY]
        5 Heads 5-6 mm high; flowering May-Jun; [habitat uncertain, Piedmont SC]
      4 Involucres 3-5 mm high; inflorescence with heads more tightly congested, with 6-15 heads on a typical 3 cm lateral branch; [river scour habitats, e. TN and cn. NC].
          6 Inflorescence axis and branches densely pubescent with arching hairs; basal leaves lanceolate to ovate, up to 35 mm wide; [known only from the Hiwassee River in e. TN]
          6 Inflorescence axis and branches glabrous; basal leaves linear-lanceolate, up to 22 mm wide [known only from the Yadkin River in sc. NC]
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Key to Solidago, Key M: Key to "Appalachian squarrose goldenrods" -- with basally disposed leaves, cylindrical inforescensce, and squarrose phyllaries [subgenus Solidago, section Squarrosae]

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1 One species; [subgenus Solidago, section Squarrosae]
1 One species; [subgenus Solidago, section Squarrosae]
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Key to Solidago, Key N: Key to "Carolina maritime goldenrods" -- with basally disposed leaves, cylindrical inforescence, and stipitate glandular phyllaries [subgenus Solidago, section Villosicarpae]

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1 One species; [subgenus Solidago, section Villosicarpae]
1 One species; [subgenus Solidago, section Villosicarpae]
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Key to Solidago, Key O: Key to "erect goldenrods" -- with basally disposed leaves and elongate, cylindrical inflorescences (subgenus Solidago, section Erectae]

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1 Phyllaries very narrow, ca. 0.5 (-0.75) mm wide, linear-lanceolate, very gradually tapering to a pointed or minutely rounded tip; [subgenus Solidago, section Erectae, series Puberulae].
  2 Stems glabrous proximally up to mid-stem; rays mostly 6-9; inner phyllaries usually striate with 2 prominent secondary veins
  2 Stems finely hairy throughout with minute strigillose hairs; rays mostly 9-16; inner phyllaries not striate.
    3 Leaves 20-50 (-60) per stem; midstem leaves usually 4-5 cm long; phyllaries attenuate; [Mountains and Piedmont of GA northward, and Coastal Plain from VA northward]
    3 Leaves (20-) 50-120 per stem; midstem leaves usually 1-4 cm long; phyllaries acute to acuminate; [Coastal Plain from DE southward]
1 Phyllaries broader, (0.75-) 1.0-1.5 mm wide at mid-length, ovate to lanceolate, acute to obtuse or broadly rounded; [subgenus Solidago, section Erectae, series Erectae].
(c) Ware, Richard & Teresa - CC-BY-NC, permission granted to NCBG
      4 Rays white
      4 Rays yellow (may turn pale yellow with age).
        5 Involucres (6-) avg. 7.2 (-9.5) mm high
        5 Involucres 3.5-6.5 mm high.
          6 Leaves and stems sparsely to densely hairy with long, spreading (to less typically appressed) hairs
          6 Leaves and upper stems glabrous or nearly so, the lower stems often somewhat hairy with short hairs (often feeling slightly scabrous).
(c) Ware, Richard & Teresa - CC-BY-NC, permission granted to NCBG
             7 Inflorescence thyrsiform, very slender, usually linear in outline but sometimes with a few widely spaced elongate branches; cypsela bodies 2.2-3.0 mm long; ray flowers often pale yellow; [MA to se. IN, south to GA and MS, mostly avoiding the Coastal Plain southward]
(c) Fleming, Gary P.
(c) Pogacnik, Shaun - CC-BY-NC, permission granted to NCBG
             7 Inflorescence panicle-like, usually with several to many ascending branches and ovoid in outline; cypsela bodies 1.1-2.0 mm long; ray florets golden yellow; [MA to GA, west to SD and scattered south from CO to ne. NM].
(c) Graeff, Alex - CC-BY-NC-ND, permission granted to NCBG
               8 Mid-stem leaves 0.4-1.5 (-2.0) cm wide; basal leaves 0.8-2.0 cm wide, entire or slightly serrate, present or absent at flowering
(c) Faulkner, Erin - CC-BY-NC, permission granted to NCBG
               8 Mid-stem leaves usually > 2 cm wide; basal leaves (2.0-) 3.0-5.5 cm wide, coarsely serrate, present at flowering