[6] Solidago altissima has diploid, tetraploid, and hexaploid populations as well as morphological variations which have generally led to classifying it into two subspecies.

Roughly speaking, these subspecies can be identified as being from the eastern and western parts of the North American continent.

At least in the Midwest, it is common to have plants of different ploidy interspersed, with little apparent tendency for one type to dominate even a fairly local geographical area.

[11] These protease inhibitors can negatively affect the digestive system of herbivores slowing growth and reproduction making them an effective mean of resistance.

[12] The production of these inhibitors is costly and can vary between populations, possibly being lower in areas that are not subject to as much predation.

This is a process in which certain individuals within a population will bow until their tops point downward in an effort to hide from egg laying insects.

[14] Insect species inject their eggs into goldenrod buds causing spherical swelling on the plant known as a gall.

[15] Members of the population with this "candy-cane" phenotype experience a lower chance of hosting eggs and having galls formed by these herbivores.

Though ducking provides S. altissima with the benefit of being able to avoid damage from insect oviposition, the fact that it occurs in a low number of individuals in populations suggests that there is a cost to having this trait, possibly preventing it from becoming the major phenotype.