The Tall Flat-topped White Asters and Purple Cascade Asters
Doellingeria Nees as recently revised includes 4 eastern and 10 western x=9 species all native to North America (Allen et al., 2019). The genus is distinguished by its fruit pappi, inflorescence shape and the brachidodromous leaf venation. Cypselae (achenes) have a quadruple pappus consisting of: 1) short bristly scales (secondary outer series), 2) mid length bristles with attenuate tips (secondary inner series), 3) longer bristles with attenuate tips (primary outer series), and 4) the longest innermost bristles with strongly clavate (flattened and widened) tips (Semple & Hood 2005). The quadruple pappus appears to be the primitive state within the North American Clade. Phyllaries are narrow with a chlorophyllous zone of narrow bands along the raised midvein. The arrays of heads are corymbiform. The leaves have a well developed prominent near-marginal connected network of lateral veins forming the distinctive brachidodromous pattern.
The genus was recognized as distinct from Aster in floras in the late 1800's and early 1900's, but subsequently was generally included in Aster s.l. following Gray (1884). Semple, Chmielewski and Leeder (1991) treated the eastern North America species as Aster sect. Triplopappus following Jones (1980) and Semple and Brouillet (1980). Nesom (1993) reviewed the taxonomy of the genus and divided it into two sections. In the RFLP cpDNA study by Xiang and Semple (1996) Eucephalus was the sister group to Doellingeria, but the study did not include other genera that may be more closely related to Doellingeria than Eucephalus. Brouillet, Allen, Semple and Ito (2001) determined that only the eastern North American species were related to Eucephalus. The representative eastern Asian species included in their study were all members of the Aster clade and thus do not belong in the genus Doellingeria which includes only species of the North American Clade of the Astereae (Brouillet et al. 2009). Allen at al. (2019) presented molecular data indicating that the three eastern species formed a clade with the western D. elegans and this groups of four species was sister to the other western species. Because D. elegans is the type species for the name Eucephalus, the two genera were merged under the older name Doellingeria. Allen et al. (2019) presented multivariate morphometric analyses showing that the three eastern species were morphologically distinct from the western species and that the three western species D. glaucescens, D. gormanii, and D. paucicapitatus were somewhat distinct (Pacific Northwest Subgroup) from the other western species (Rocky Mt.-Cascade Subgroup)
Allen, Brouillet and Semple (2001) explored relationships and geographic patterns of subclades within the Eucephalus-Doellingeria clade. They found that two species, H. glauca (A. glaucodes) and H. wasatchensis, usually included in Eucephalus belonged in the Eurybia group, as Nesom (1994) had proposed, but based on DNA data are now included in Herrickia (Brouillet 2006).
- Doellingeria elegans (syn: Aster perelegans)
Rocky Mt.-Cascade Subgroup
- Doellingeria breweri (syn: Chrysopsis b.; Heterotheca b.)
- Doellingeria engelmannii
- Doellingeria glabrata
- Doellingeria ledophylla
- Doellingeria tomentella (A. brickellioides)
- Doellingeria vialis
Pacific Northwest Subgroup
Allen, G.A.*, L. Brouillet, and J.C. Semple, J.C. 2001. A molecular phylogeny of the Eucephalus asters
(Asteraceae) based on ITS sequences, with biogeographic and morphological inferences. CBA/ABC Meeting, Kelowna, BC, June 2001. http://www.sci.ouc.bc.ca/biol/CBA/abstract.html
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.
Allen, G.A. 2006. Eucephalus Nuttall. pp. 39-42. In Flora North America Editorial Committee, eds. Flora of North America. Vol. 20. Asteraceae, Part 2. Astereae and Senecioneae. Oxford University Press, New York.
Brouillet, L. 2006. Herrickia Wooton & Standley. pp. 361--365. In Flora North America Editorial Committee, eds. Flora of North America. Vol. 20. Asteraceae, Part 2. Astereae and Senecioneae. Oxford University Press, New York.
Allen, G.A., L. Brouillet, J.C. Semple, H.J. Guest, and R. Underhill. 2019. Diversification of the North American Doellingeria-Eucephalus Clade (Astereae: Asteraceae) as inferred from molecular and morphological evidence. Syst. Bot. 44(4): 930-942.
Allen, G.A., L. Brouillet, J.C. Semple, H.J. Guest, and R. Underhill. 2019. Data from: Diversification of the North American Doellingeria-Eucephalus Clade (Astereae: Asteraceae) as inferred from molecular and morphological evidence. Dryad Digital Repository. https:/doi.org/10.1600/036364419X15710776741477
Revised 30 April 2021 by J.C. Semple
© 2021 J.C. Semple, including all photographs unless otherwise indicated