Eurybia Divaricata - Similar Species

Similar Species

Several different plants are superficially quite similar to the white wood aster, but close examination as well as knowledge of the plants' differing habitats and ranges can readily distinguish them. The most similar species is the mountain wood aster (Eurybia chlorolepis), which was previously considered conspecfic with E. divaricata. E. chlorolepis differs in having flower stalks that are longer than 1.5 cm, while those of E. divaricata are shorter than this. The involucres of the mountain wood aster are generally between 6.5 and 9 mm in length, while those of the white wood aster are normally from 4.2 to 6.5 mm long, but in rare cases they may be as long as 7.5 mm. The mountain wood aster almost always has more rays than the white wood aster: the former usually has 12 to 16, but occasionally as few as 10, while the latter generally has 5 to 10 and never more than 12. The rays are also longer on the mountain wood aster at 17 to 18 mm in most cases, while the white wood aster's are generally only 10 to 15 mm. Lastly, E. chlorolepsis is only present from southern Virginia south to Georgia in the Appalachian Mountains at altitudes of 1200 to 2000 metres, while E. divaricata can be found from southern Canada south to Alabama, meaning their ranges only overlap in the southern United States, and there only at high elevations.

Another species commonly confused with the white wood aster is Schreber's aster (Eurybia schreberi). Schreber's aster is typically found on moister soils, though it can also be found on mesic sites. While much of their ranges overlap, Schreber's aster is not found south of Virginia or Tennessee. Schreber's aster can also be distinguished by the more numerous teeth on the leaves, typically numbering 15 to 30 per side to the white wood aster's 6 to 15 per side. The leaves are wider on Schreber's aster with broader sinuses at the bases. The flower stalks are also densely hairy on the white wood aster, while they are only sparsely haired on Schreber's aster. Lastly, the clones of E. schreberi have sterile rosettes, while those of E. divaricata do not.

Two more superficially similar plants include the bigleaf aster (Eurybia macrophylla) and the heartleaf aster (Symphyotrichum cordifolium), though both usually have blue or pale blue rays, while those of E. divaricata are always white. Both species sometimes have white rays in rare cases, but E. macrophylla can still be distinguished by its larger and broader leaves and S. cordifolium by its straighter and branched stems.