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Key to Boltonia

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1 Achenes with pappus reduced to a short ring of bristles to 0.15 mm long or with occasional slender awns to 0.6 mm; achene wings lacking or up to 0.1 mm wide; faces of achenes glabrous.
  2 Phyllaries 0.2-0.5 mm wide, whitened throughout or with greenish tip, midrib relatively prominent (25-35% phyllary width); heads 4.3-6.1 mm wide, peduncles 0.25-0.5 mm in diameter; ray corollas white fading to pinkish in age; bracteal leaves narrowly oblanceolate to linear; [of Coastal Plain and Piedmont of VA southward]
  2 Phyllaries 0.4-0.9 mm wide, whitened in lower 1/3 to 1/2 only, distal portion green, midrib relatively narrow (8-14% phyllary width); heads 6-11.5 mm wide, peduncles 0.5-1.1 mm in diameter; ray corollas lilac or pinkish (-white); bracteal leaves oblanceolate to oblong; [of Mountains of VA (Augusta County) northward]
1 Achenes with two distinct pappus awns in addition to a shorter ring of bristles, the awns mostly 0.3-1.8 mm long; achene wings obvious, mostly 0.2-0.5 mm wide; faces of achenes pubescent.
    3 Cauline leaves decurrent on the stem; rhizomes and stolons absent
    3 Cauline leaves not decurrent on the stem; rhizomes or stolons present or absent.
      4 Phyllaries spatulate, oblanceolate, or linear-oblanceolate, apices cuspidate, pappus awns 0.6-1.0× as long as the achenes; inflorescence diffusely branched, with numerous heads.
        5 Phyllaries spatulate to obovate-spatulate, (2-) 2.5-6 mm wide, membranaceous margins broad
      4 Phyllaries linear-subulate to lanceolate; pappus awns 0.2-1.0× as long as the achenes; inflorescence various.
               8 Inflorescence diffusely branched, heads relatively numerous, phyllaries (0.2-) 0.3-0.4 (-0.5) mm wide, (1.3-) 1.4-1.8 (-2.1) mm long, pappus awns 0.3-0.8 mm long
               8 Inflorescence with loosely ascending branches, heads relatively few, phyllaries (0.5-) 0.7-0.9 (-1.1) mm wide, (1.5-) 2.1-2.4 (-3.5) mm long, pappus awns (0.2-) 0.8-1.1(-1.3) mm long.
                 9 Plants reproducing vegetatively by basal offsets, culms ascending, leaves elliptic to obovate with rounded or blunt apices, held at various angles from culm and inflorescence branches, plants with weak apical dominance; [of the Susquehanna River of MD and PA]
                 9 Plants reproducing vegetatively by elongate stolons, culms more strictly erect, leaves lanceolate with acute apices, the leaves oriented at an acute angle to the culm and inflorescence branches, plants with relatively strong apical dominance; [more widespread in our area]
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