Symphyotrichoid Asters in the restricted sense
Symphyotrichum Nees in the narrow sense includes all the many x=8, 7, 6, 5 and 4 species of asters native to North America (Semple et al. 2002). Several species are naturalized in Europe (S. lanceolatum, S. novi-belgii). Neither of these has glandular phyllaries. Species are distinguished on the basis of differences in habit, leaf shape and bases, involucre size, phyllary shape and chlorophyllous zone pattern, and fruit traits. Semple and Hood (2005) described the details of pappus variation in the genus. Brouillet et al. (2006 FNA) covered 77 of the ca. 90 species in the genus.
Summary of the classification of Symphyotrichum s.s.
- Chapman's Aster (x =7 basal species)
- Symphyotrichum/Punicei Group (typical symphyotrichoid and puniceoid x=8 asters)
- Foliacei Group (western x=8 symphyotrichoid asters)
- Dumosi Asters (dumosum like x=8 symphyotrichoid asters)
- Heterophylli Asters (heart-leaved x=8 symphyotrichoid asters)
- Porteriani Asters (old field symphyotrichoid asters)
- Turbinate Asters (x=48, turbinate symphyotrichoid aster)
- Conyzopsoid Asters (x=7 salt flat symphyotrichoid asters)
- Astropolium Asters (x=5 salt marsh oxytripolioid asters)
- Virguloid Asters (x =5, mostly cormoid symphyotrichoid asters)
- Allopolyploid Ascendentes Asters (x=13, 21, western Foliacei-like asters)
Semple, J.C. and J.L.A. Hood. 2005. Pappus variation in North American Asters. I. Double, triple and quadruple pappus in Symphyotrichum and related aster genera (Asteraceae: Astereae). Sida 21: 2141--2159.
Brouillet, L., J.C. Semple, G.A. Allen, K. Chambers and S. Sundburg. 2006. Symphyotrichum Nees. pp. 465-539. In Flora North America Editorial Committee, eds. Flora of North America. Vol. 20. Asteraceae, Part 2. Astereae and Senecioneae. Oxford University Press, New York.
revised 18 Feb 2014 by J.C. Semple
© 2014 J.C. Semple, including all photographs unless otherwise indicated