Vascular Plants of North Carolina
Account for Crooked-stem Aster - Symphyotrichum prenanthoides   (Muhlenberg ex Willdenow) Nesom
Members of Asteraceae:
Members of Symphyotrichum with account distribution info or public map:
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Section 6 » Order Asterales » Family Asteraceae
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Author(Muhlenberg ex Willdenow) Nesom
DistributionMountains only, at middle to high elevations.

Western MA to southern Ont. and MN, south to NC, TN, IL, IA.
AbundanceInfrequent to fairly common, but quite local. Oddly lacking specimen records for heavily collected Buncombe and Madison counties, plus several others in the central Mountains.
HabitatRich cove forests, montane deciduous-conifer forests, montane seepage bogs. Typically a forest interior species, or at least in moderate shade -- and usually in somewhat moist places.
PhenologyFlowering and fruiting late August-October.
IdentificationAs its name suggests, the stem is crooked: angled one way, then the opposite, for several nodes. However, the best clue to identity is the leaf shape: ovate to narrowly ovate, taper-pointed, sharply toothed, and with a winged, tapered stalk that clasps around the stem. The inflorescence is somewhat elliptical in outline (or sometimes broader than long), with long, pale blue or lavender-blue rays and yellow disks. Wavyleaf Aster (S. undulatum) may appear similar, but its leaves are cordate (heart-shape sinus) at the junction of the blade and stalk (vs. tapered to the winged stalk). Also, involucral bracts of Wavyleaf Aster are acute or blunt (vs. acuminate).
Taxonomic CommentsNOTE: The genus Aster was examined by G.L. Nesom (1994), who determined that it was composed of a number of discrete genera (a few of which were already split off by authors as Sericocarpus, Ionactis, etc.). The earliest available name for North American "Aster" is Symphyotrichum, a name regrettably long and hard to spell.

Other Common Name(s)Crooked Aster
State RankS3? [S3]
Global RankG4G5
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B.A. SorrieBuck Creek Barrens, developing plant, June 2021. ClayPhoto_natural
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