SymphyotrichumÌý²õ³Ü²ú²µ.ÌýVirgulusÌý(Raf.) Nesom includes mostlyÌýx=5 species plus oneÌýx= 30 and twoÌýx=4 species of North American asters. These have been treated as a genus (Lasallea,ÌýVirgulus) or as a subgenus withinÌýAsterÌýorÌýSymphyotrichum. Semple and Brouillet (1980) were the first to recognize the group. Species generally share cormoid rhizomes and similar basal rosette leaves and often patent branching as well as a distinctive karyotype, but they differ greatly in the upper leaf and head array traits. Most species occur in the eastern United States, with some native to western North America from Alaska and the northern Yukon to southern Mexico.
Morgan and Holland (2012) using ITS and ETS sequence data demonstrated that there was likely reticulate evolution of involving some species of Symphyotrichinae.Ìý Symphyotrichum gypsophila may be related to Ampelaster.Ìý The Mexican virguloid species are likely related to Psilactis rather than subg. Virgulus, which itself may belong in a clade with Almutaster and Psilactis rather than Symphyotrichum.Ìý Further work is need to clarify generic limits and relationships in the Symphyotrichinae.Ìý The treatment of taxa by Brouillet et al. (2006 FNA) is followed below with some modifications.
Classification and Illustrations
SymphyotrichumÌýSect.ÌýConcolores
- Symphyotrichum concolor
- Symphyotrichum plumosum
- Symphyotrichum lucayanumÌý(Bahamas)
- Symphyotrichum pratense
- Symphyotrichum sericeum
SymphyotrichumÌýSect.ÌýGrandiflorae
- Symphyotrichum campestre
- Symphyotrichum fendleri
- Symphyotrichum fontinale
- Symphyotrichum estesii
- Symphyotrichum grandiflorum
- Symphyotrichum oblongifolium
- Symphyotrichum pygmaeum
- Symphyotrichum yukonense
Ìý Ìý Ìý Ìý Mexican (may not belong in genus)
- Symphyotrichum hintonium
- Symphyotrichum moranense
- Symphyotrichum trilineatum
SymphyotrichumÌýSect.ÌýPatentes
ÌýÌýSymphyotrichumÌýsubsect.ÌýPatentes
ÌýÌýSymphyotrichumÌýsubsect.ÌýBrachyphylli
SymphyotrichumÌýSect.ÌýPolyliguli
Symphyotrichum ×amethystinumÌý(S. novae-angliae × S. ericoides)
SymphyotrichumÌýSect.ÌýEricoides
Morgan, D.R. and B. Holland. 2012. Systematics of Symphyotrichinae (Asteraceae: Astereae): Disagreements Between Two Nuclear Regions Suggest a Complex Evolutionary History. Syst. Bot. 37: 818–832.
Last updated 16ÌýOctoberÌý2019 by J.C. Semple
© 2019, J.C. Semple, including all photographs unless otherwise indicated