Blue-Stemmed Goldenrod vs Mountain Decumbent Goldenrod
This guide is under construction and has not been published yet. It may have errors. When in doubt, double-check other sources for definitive ID.These two species are closely-related, visually similar, and occupy similar habitats. They can usually be distinguished by closely examining their stems, growth habit, and lower leaves, and they have a few other subtle differences. S. curtisii is restricted to the Southern Appalachians, prefers moister conditions, and tolerates greater shade. S. caesia has a much broader range, is more common at lower elevations, and ranges into sunnier, drier conditions.
Blue-Stemmed Goldenrod (Solidago caesia) | Mountain Decumbent Goldenrod (Solidago curtisii) |
A perennial of upland decidous woodlands, native to Eastern North America. | A perennial of rich mesic deciduous forests in the Southern Appalachians. |
 Stem is usually glaucous (with a pale waxy coating that can be removed) and is a reddish-purple color underneath the coating, often leading it to look bluish. Photo © Bob Schwartz, CC BY 4.0. |  Stem is a simple green color, neither being glaucous, nor having a reddish-purple hue. Photo © Brandon Wheeler, Public Domain. |
 In the absence of supporting vegetation, stems tend to lean, sprawl, or flop over. Photo © treelogical, CC BY 4.0. |  Stems tend to stay upright, supporting their own weight even in the absence of supporting vegetation to lean against. Photo © Alan Weakley, Public Domain. |
 Leaves average narrower, and are rarely more than 20mm wide, almost never more than 30mm wide. Photo © Robert Simcox, CC BY 4.0. |  Some lower leaves may be much broader (commonly to 43mm, sometimes wider) Photo © Michael J. Papay, CC BY 4.0. |
 Flower clusters are more secund, i.e. with the flowerheads pointing in more-or-less the same direction, usually upwards (relative to gravity, not the tip of the stem.) Photo © Tom Scavo, CC BY 4.0. |  Flower clusters are less secund, i.e. with the flowerheads projecting in many different directions. Photo © Ken Kneidel, Public Domain. |
 Plants average fewer flowerheads (9–380) and tend to have fewer relative to the robustness of the plant. Photo © botany08, CC BY 4.0. |  Plants average more flowerheads (20–800) and tend to have more relative to the robustness of the plant. Photo © Brandon Corder, CC BY 4.0. |
Additional Notes
The broader leaves of S. curtisii reflect its greater shade-tolerance, whereas the anthocyanins leading to the reddish-purple color of the stem of S. caesia reflect adaptation to higher-light conditions during the time when its stem is developing.References & External Resources
These short lists show only links helpful for ID. For a complete list of references and resources also covering other aspects of ecology, visit the links section of the full article on each plant, which is the first entry here.
