Goldenrods are mostly tall and showy plants with yellow flowers – rods of gold. In French, they are called verge d’or, batons or sticks of gold. Where they are indigenous or introduced, they are often among of the most conspicuous wildflowers of summer. Their flowers are blamed (without justification) for stimulating allergies. Their leaves and stems contain fragrant resins. As weeds, they quickly overtake abandoned farm fields, and are invasive in many parts of the world. Their flowers produce huge numbers of wind-blown seeds, yet the plants are perennial.
Dozens of species of goldenrods arose from a common ancestor, and this group has been given the technical name Solidago. The name begins with Latin (and English) for “solid,” and they are indeed tough weeds. The name might also refer to the “solidus,” a type of gold coin minted by the Roman Empire. The suffix suggests healing properties, in agreement with another common name, “woundwort,” applied to goldenrods and other herbs used to treat wounds. Like the coin, the weed was golden and could be trusted.
In pastures, livestock avoid goldenrods, yet there are many species of insects that eat them, sometimes only them. Spiders spin webs on them or between them, or spin no web at all and use the plant as a platform for hunting. Bees and butterflies (and more) visit the flowers by day, then moths and male mosquitoes (and more) visit by night. Other arthropods, some of them tiny, inhabit portions of the plant, above and below ground.
Following the lead of many other researchers, writers and bloggers, I will explore the world of goldenrods. I hope you find something that interests you, and that will allow you to explore goldenrods, and other things, on your own.
It can be tricky to identify some species of goldenrod, but there are several guides to help you. Flora North America covers (as the name implies) the entire continent, and it uses a two-part key for Solidago that will eventually get you to the species. This publication is the impressive effort of many botanists: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=130659
Gray’s Manual of Botany includes the species of eastern and central North America. Some of the names have been changed (taxonomists do that), but you can find the current name with a quick search on line.
Nathanial Britton and Addison Brown wrote An Illustrated Flora of the Northern United States and Canada, available in many libraries. The names are more likely to be out of date than those in Gray’s Manual, but the geographic coverage might be what you need.
For the northeastern portion of North America, try Flora Novae Angliae by Arthur Haines, a recent compendium of New England vascular plants; or A Field Guide to Wildflowers by Roger Tory Peterson and Margaret McKenny; or Newcomb’s Wildflower Guide by Lawrence Newcomb.
There are more specific guides or lists of plants for states, counties and regions, such as those published by the New England Botanical Club: http://www.rhodora.org/specialpublications/publications.html. These might be just what you need to confirm whether a species of goldenrod is known to grow in a particular location.