Symphyotrichoid Asters in the broad sense
Subtribe Symphyotrichinae Nesom (sensu Nesom 2000) includes x = 9, 8, 7, 6, 5, 4 and 3 species of asters native to North America. A few species are native to South America and several species are naturalized in Europe and scattered locations around the globe. This is the largest group of asters and the most common throughout North America. These are the asters with paniculiform inflorescences and phyllaries with a more or less diamond shaped darker chlorophyllous zone, with considerable variation in degree of leafiness and size of the chlorophyllous zone. Quadruple, triple, and double pappi occur in the subtribe (Semple & Hood 2005). Usually the secondary outer series of short bristly scales is absent or vestigial. The secondary inner series of mid lenth attenuate bristles is often weakly developed or absent. The innermost primary inner series bristles are the longest and very weakly to moderately clavate.
The Symphyotrichinae as first proposed by Nesom included a number of genera not closely related within the Tribe Astereae, but Nesom (2000) removed these and included the following genera: Canadanthus (x=9; 1 sp.); Ampelaster (x=9; 1 sp.), Almutaster (x=9; 1 sp), Psilactis (x=3,4, 9; 6 spp.), Symphyotrichum (x=8, 7, 6, 7,5,4; ca. 90 spp.). This has been shown to be a monophyletic group by Brouillet et al. (2001a, b).
revised 30 January 2014 by J.C. Semple
© 2013, 2014 J.C. Semple, including all photographs unless otherwise indicated