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Key to Asteraceae, Key G: Herbaceous composites with the leaves alternate, the heads lacking rays, and with 0 pappus

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1 Receptacle paleate (bearing receptacular bracts which individually subtend at least some of the flowers of the head).
  2 Involucres absent or vestigial, usually with 0 phyllaries; heads very small, < 6 mm high, < 4 mm wide; annuals, < 4 dm tall; disc corollas hidden or dingy in color; [tribe Gnaphalieae]
    3 Bisexual flowers (1-) 2-10 (-11), pappus of (11-) 13-28+ bristles visible in heads; functionally staminate flowers 0.
      4 Receptacles cylindric to clavate (5-15× as tall as the diameter); most pistillate paleae open to ± folded (at most each enfolding, not enclosing a floret; apices acuminate to aristate); innermost paleae erect to ascending in fruit; cypselae mono- morphic (the outer ± equaling the inner)
      4 Receptacles fungiform to obovoid (0.4-1.6× as tall as the diameter); most pistillate paleae ± saccate, each ± enclosing a floret, apices blunt; innermost paleae spreading in fruit; cypselae dimorphic (the outer longer than the inner)
    3 Bisexual flowers 0 or 2-7, pappi 0; functionally staminate flowers 0 or 2-5, pappi 0 or of 1-10 (-13) bristles hidden in heads
        5 Paleae of the bisexual or staminate flowers flat to concave, not enclosing florets, apices entire; cypselae glabrous; [mainly west of the Mississippi River, rarely east (as in MS, AL, GA, and SC]
        5 Paleae of the bisexual flowers saccate, each enclosing a floret, apices 2-fid or 3-fid; cypselae (at least the outer) strigose; [se. Texas]
  2 Involucres present, conspicuous, of many phyllaries; heads larger, 2-20+ mm wide; perennials or coarse annuals, 2-25 dm tall; disc corollas apparent, yellow, white, or pink to purplish.
          6 Disc flowers yellow or greenish yellow; [either native of s. TX southwards, or a waif]
             7 Phyllary margins and tips scarious; fresh foliage aromatic
             7 Phyllary margins and tips herbaceous; fresh foliage not aromatic
          6 Disc flowers white or whitish to pink or purple; [collectively widespread].
               8 Heads in corymbiform arrays; heads bisexual; involucres not burlike or nutlike, lacking tubercles or hooked or straight prickles or spines; leaves lanceolate, unlobed, cuneate at base
                 9 Heads lacking ray flowers; disc flowers pink (rarely nearly white); [Coastal Plain; FL and GA]
                 9 Heads with 5 white (fading to cream), scoop-shaped, inconspicuous ray flowers (keyed here as a 'failsafe'); disc flowers white; [widespread in our region]
               8 Heads in spiciform or racemiform arrays; heads unisexual (each head either with only female or only male flowers); involucres burlike, with tubercles or straight or hooked spines or prickles; leaves ovate or broader (in outline), often pinnatifid or bipinnatifid, truncate, cordate, or cuneate at base; [collectively widespread in our region].
                   10 Involucres of pistillate heads (burs) 1-4 mm long, with (1-) 5-12+ straight spines; larger leaves bipinnatifid
                   10 Involucres of pistillate heads (burs) 10-40 mm long, with 30-75+ hooked prickles; phyllaries larger leaves pinnatifid or unlobed
1 Receptacle epaleate (lacking receptacular bracts individually subtending flowers, but the receptacle sometimes bearing bristles, setae, hairs, or pits with laciniate margins.
                     11 Flowers white, pink, purple, or bluish.
                       12 Annuals, (1-) 2-10 (-30+) cm tall; corollas whitish, inconspicuous, absent on most of the (pistillate) flowers; leaves 2-3× pinnati-palmately lobed into linear segments; cypselae with an apical spine
                       12 Perennials, 10-150 cm tall; corollas at least light pink and often darker pink, purple, or blue, conspicuous, present on all flowers; leaves pinnately lobed or entire, the segments not linear; cypselae not spined.
                          13 Heads ovoid, 10-21 mm long; flowers 15-40 mm long, with long, narrow lobes; phyllaries >30, in 6+ series, and the apices often with a fringe of appendages and/or a spine tip; basal and lower stem leaves usually pinnately lobed (to entire and unlobed); [widespread in our region, especially northwards]
                          13 Heads cylindrical, 2-6 mm long; flowers ca. 3 mm long, with deltate lobes; phyllaries 12-15 in 2-3 series, herbaceous and unadorned; basal and lower stem leaves entire and unlobed; [Coastal Plain of FL and GA]
                     11 Flowers yellow, cream, or rarely red-tinged.
                            14 Leaf blades unlobed.
                              15 Heads 3-4 (-6) mm in diameter, solitary; plants 0.3-3 dm tall; [ballast waif, especially in wet, saline places]
                              15 Heads (3-) 5-20+ mm in diameter, solitary or borne in corymbiform or paniculiform arrays; plants 1.5-15 dm tall.
                                16 Involucres 8-20+ mm in diameter; cypselae 1.5-4.5 mm long
                                16 Involucres (3-) 5-8 (-10) mm in diameter; cypselae 1.5-2 mm long
                            14 Leaf blades 1-3× pinnately or palmately lobed into linear or spatulate segments.
                                  17 Annual 0.1-5 dm tall.
                                    18 Disc corollas cream to pale yellow, 0.5-0.8 mm long; fresh plants malodorous; [waif]
                                    18 Disc corollas greenish yellow, 1.1-1.3 mm long; fresh plants pineapple-scented; [common weed, especially northwards in our region]
                                  17 Perennial, biennial or annual 4-15 dm tall.
                                       19 Heads borne in paniculiform, racemiform, or spiciform arrays, never flat-topped; flowers < 50 per head
                                       19 Heads borne in corymbiform arrays; flowers 60-300+ per head

Key to Asteraceae, Key L: Herbaceous composites with the leaves alternate or basal and the heads radiate, the rays white, pink, purple, and the 0 pappus

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1 Rays primarily pink or purple, not white-tinged (flowers viewed from above, adaxial surface of the rays).
image of plant
Show caption*© Jacek Pietruszewski, some rights reserved (CC BY), uploaded by Jacek Pietruszewski
  2 Receptacles epaleate; leaves pinnatisect; [waif, ne. US]
image of plant
Show caption*© Scott Ward
image of plant
Show caption*© Dan Spaulding, some rights reserved (CC BY-NC), uploaded by Dan Spaulding
  2 Receptacles paleate; leaves simple or bladeless; [widespread natives]
image of plant
Show caption*© Dan Spaulding, some rights reserved (CC BY-NC), uploaded by Dan Spaulding
image of plant
Show caption*© Alan Cressler: Coreopsis nudata, Apalachicola National Forest, Franklin County, Florida 2 by Alan Cressler
    3 Leaves without blades (the petioles terete, appearing Juncus-like); ray florets pink or purplish; disc florets fewer (60-120+), the corollas usually yellowish; [wet pinelands and seepages]
image of plant
Show caption*© Scott Ward
image of plant
Show caption*© Keith Bradley
    3 Leaves broad and conspicuous; ray florets purple; disc florets many (200+), the corollas pink, green, red, purple, or yellow colored; [plants of prairies and similar habitats]
1 Rays primarily white to white-tinged or yellow throughout (lamina of the ray with at least some white basally if not uniformly yellow).
      4 Disc florets functionally staminate (thus cypselae only forming from ray florets)
      4 Disc florets bisexual, fertile.
        5 Leaves entire or toothed, but not deeply pinnatisect; sometimes with smaller rounded lobes (Leucanthemum basal leaves can have deeper, round lobes); plants usually not aromatic.
          6 Stem internodes usually winged (at least proximally)
          6 Stems not winged.
             7 Leaves primarily basal, the cauline leaves absent or fewer and much reduced in size from basal leaves; abaxial surface of the ray laminae white or sometimes pink-tinged (on live plants) but lacking a prominent colored midstripe.
               8 Leaves strigose, the margins crenate-serrate; roots not red-tipped; abaxial surface of ray laminae often pink or purple tinged, flowers closing at night
               8 Leaves glabrous (or faces sparsely hairy), the margins entire or toothed; roots usually red-tipped; rays drying pinkish but abaxial surface not conspicuously pink tinged on live plants
             7 Plants with well-developed cauline leaves, the margins entire or sometimes toothed (usually entire in Aphanostephus, occasionally deeply lobed); abaxial surface of the ray lamina sometimes white, but often with a prominent purple or blue midstripe (except Leucanthemum, which merely dries pink)
                 9 Flowering heads smaller, arranged in corymbiform or paniculiform arrays; ray florets with diminuitive laminae (0.3-5.0 mm long), heads thus sometimes superficially appearing disciform (rays sometimes double in horticultural forms as in Achillea ptarmica)
                   10 Plants aromatic; leaves linear to narrowly lanceolate, the surfaces glabrous or sparsely hairy; pales more or less folded but lacking distal papillae; cypselae not shed along with subtending phyllary and disc florets; [tribe Anthemideae]
                   10 Plants not aromatic; leaves variously shaped, at least some usually lyrate or oblanceolate (not all linear), the surfaces hairy and gland-dotted (at least abaxially); pales distally pappilate or fimbriate; cypselae shed along with subtending phyllary and 2 disc florets each invested in a pale; [tribe Heliantheae]
                 9 Flowering heads larger, singular on scapes (if in 2's or 3's, these large and not in broad corymbiform arrays), rays prominent, the laminae usually > 10 mm long
                     11 Rays white abaxially (drying pinkish); receptacles broadly convex, not pitted; plants rhizomatous perennials; pappus absent; [tribe Anthemideae]
                     11 Rays white or with prominent blue or purple midstripe (sometimes present after drying); receptacles conic, pitted; plants tap-rooted annuals (except Astranthium riddellii); pappus absent, coroniform, or of scales; [tribe Astereae]
                       12 Phyllaries scarious margined; cypselae 4-angled and with 4-12 thick ribs, pappus absent, of scales or coroniform; ray florets closing distally at night
                       12 Phyllaries sometimes hyaline but not scarious margined; cypselae compressed, lacking prominent ribs (though sometimes glochidiate), pappus absent or short coroniform; ray florets not closing at night
        5 Leaves deeply lobed or pinnatisect, the ultimate segments linear or if rounded, the sinuses of the lobes nearly reaching the midrib (pinnatifid); plants typically aromatic (except Tripleurospermum and Parthenium); [tribe Anthemideae].
                          13 Receptacles paleate (chaffy or with apparent bracts), the pales sometimes distally fimbriate or papillate (Parthenium).
                            14 Stem internodes usually winged
                            14 Stems not winged.
                              15 Rays (the laminae) white with conspicuous yellow coloration at the bases
                              15 Rays primarily white to white-tinged (without strong yellow color at the base of the laminae) or yellow throughout (lamina of the ray with at least some white basally; if rays are white).
                                16 Flowering heads smaller, arranged in corymbiform or paniculiform arrays; ray florets with diminuitive laminae (0.3-5.0 mm long); ray and disc florets both white or white-ish.
                                  17 Plants usually aromatic; pales more or less folded but not distally fimbriate or papillate; cypselae not shed along with phyllary and disc florets; [tribe Anthemideae]
                                  17 Plants not aromatic (at least not conspicuously so); pales distally fimbriate or papillate; cypselae shed along with subtending phyllary and 2 disc florets each invested in a pale; [tribe Heliantheae]
                                16 Flowering heads larger, arranged mostly singular at the ends of scapes, not in broad corymbiform arrays (except Tripleurospermum, which has larger heads and prominent rays), ray laminae prominent; ray and disc florets differing in color (rays typically white; discs typically yellow).
                                    18 Plants annual, erect or decumbent, ill-scented or not; ultimate leaf margins dentate to lobed; cypsela ribs usually 9-10 (sometimes lacking); [widespread non-natives]
                                    18 Plants perennial and prostrate (mat-forming), aromatic; ultimate leaf margins entire; cypsela ribs weak; [waif, ne. US]
                          13 Receptacles epaleate (lacking chaff).
                                       19 Ultimate leaf lobes broad, ovate-shaped (not linear)
                                       19 Ultimate leaf lobes linear.
                                         20 Plants usually aromatic; maturing flowering heads with deflexed ray laminae; cypsela 5-ribbed, lacking apical resin sacs
                                         20 Plants not aromatic; ray laminae not deflexed; cypsela with 3 ribs and 1-5 abaxial-apical resin sacs

Key to Asteraceae, old Key J: Herbaceous composites with the leaves alternate or basal and the heads radiate, the rays white, pink, purple

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1 Receptacles chaffy (paleate).
  2 Phyllaries dry, scarious-margined.
    3 Ray florets 1-5 mm long; heads small in corymbiform arrays
    3 Ray florets > 5 mm long; heads large, terminating the branches
  2 Phyllaries herbaceous, not scarious on margins.
      4 Ray florets < 2.5 mm long; disk florets sterile, with an undivided style
      4 Ray florets > 5 mm long; disk florets fertile, with a divided style.
        5 Ray florets pink or light purple, > 15 mm long; heads single
        5 Ray florets white, 5-10 mm long; heads 20-100 in a compound corymb
1 Receptacles naked (epaleate).
          6 Pappus absent or coroniform.
             7 Achene faces minutely glandular-glochidiate (bearing small gland-like bristles)
             7 Achene faces glabrous or short-strigose but not glandular-glochidiate.
               8 Leaves basal; cypselae marginally 2-ribbed; mature plants < 2 dm tall
               8 Leaves cauline (and sometimes also basal); cypselae with ± 10 ribs; mature plants > 2 dm tall
                 9 Heads solitary or 2-3 in corymbiform arrays
                 9 Heads 5-60+ in corymbiform arrays
          6 Pappus present, of bristles or scales.
                   10 Heads primarily discoid with reduced ray florets
                   10 Heads radiate with conspicuous ray florets.
                     11 Taprooted annuals; ray florets 1-7 mm long.
                       12 Leaves and stems not fleshy, rarely glabrous; cypselas < 1.4 mm long
                       12 Leaves and stems fleshy, mostly glabrous; cypselas > 1.4 mm long
                     11 Not taprooted and mostly perennials; ray florets > 3 mm long.
                          13 Ray florets usually > 60; blooming Apr-Oct
                          13 Ray florets usually < 60; blooming late May-Nov.
                            14 Receptacles hemispheric to conic; pappus often with 2-4 awns (Boltonia) or lacking awns and coroniform (Astranthium).
                              15 Achenes not narrowly winged, the surfaces minutely glandular-glochidiate (bearing small gland-like bristles)
                              15 Achenes narrowly winged, the surfaces sometimes puberulent but not glandular-glochidiate
                            14 Receptacles flat to slightly convex; pappus lacking awns.
                                16 At least the basal and lower leaves both petiolate and cordate/subcordate at base.
                                  17 Often colonial; inflorescence corymbiform, flat-topped or rounded; outer phyllaries > 1 mm broad
                                  17 Not colonial; inflorescence paniculiform, often elongate; outer phyllaries < 1 mm broad
                                16 Basal and lower leaves not both petiolate and cordate/subcordate at base.
                                    18 Leaves sessile and auriculate or cordate-clasping
                                    18 Leaves petiolate or epetiolate but not auriculate or cordate-clasping.
                                       19 Cypselas glandular; pappus double
                                       19 Cypselas not glandular; pappus single or double or in four series.
                                         20 Leaves silvery-silky on both sides (at least when young), entire
                                         20 Leaves not silvery-silky, entire or toothed.
                                           21 Pappus double, with inner bristles distinctly longer than outer bristles.
                                             22 Leaves not rigid, veiny, lanceolate to elliptic or ovate, > 6 mm wide
                                             22 Leaves rigid, 1-nerved, linear to linear-spatulate, < 5 mm wide
                                           21 Pappus simple with all bristles often about the same length.
                                               23 Ray florets white, few (usually 3-8); cypselas densely silky
                                               23 Ray florets white to pink or blue or purple, more numerous (usually 8-30); cypselas glabrous to pubescent but not densely silky.
                                                 24 Ray florets white; involucres < 6 mm long; phyllaries < 1 mm wide
                                                 24 Ray florets white or pink to blue or purple; involucres 7-12 mm long; phyllaries usually > 1 mm wide.
image of plant
Show caption*© Scott Ward
                                                    25 Phyllaries glandular
                                                    25 Phyllaries not glandular.
                                                      26 Phyllaries long-attenuate or loose and spreading
                                                      26 Phyllaries appressed, not long-attenuate.
                                                        27 Plants coarse-hairy; lowest leaves > 5 cm wide
                                                        27 Plants glabrous to hairy; lowest leaves < 3 cm wide