Keeping the goldenrod seed heads straight

This year, some of the late goldenrods are just ready to collect. There are actually three goldenrod species that are "ready" now, but only two of them are worth collecting. With experience, these three goldenrods are fairly easy to tell apart, but since they are all in seed set right now, one has to pay attention to be sure they don't get mixed up.


Showy goldenrod (Solidago speciosa), in particular, seems to have been slow in forming good seed heads, but yesterday they were just perfect for collecting. Showy goldenrod is colonial, forming compact patches, with all the stems arising from a single root stock. Its stems are smooth and red, and its seed heads are columnar.

We have showy goldenrods growing all over Pleasant Valley Conservancy, in both prairies and savannas, but they are all descended from a single small prairie remnant that is at the east end of Toby's Prairie. This is still one of our best collecting sites for this handsome species.
























Gray goldenrod (S. nemoralis) is a dry-site species that thrives fairly well, and we have been collecting lots of seeds this year to use in our East Basin seed mix. It is a fairly small species and is neither clonal or colonial. Its inflorescence is small and the flowers are all formed from one side, so that the flower head has a tendency to nod. (One common name for this species is "nodding goldenrod"). An important diagnostic characteristic of gray goldenrod are the white hairs on the stem, which are generally more visible now when the plant is in seed.

Gray goldenrod is a very desirable species in planted prairies, and does especially well in a dry-mesic seed mix.











The third species, Canada goldenrod (S. canadensis), does not need any help from us. In fact, we spend a fair bit of time each season trying to get rid of it. Canada goldenrod is a clonal species, spreading by rhizomes, and can form large patches. Its seed heads are loose and spreading. Although the seed heads seem quite distinct in the photos shown here, in the field it can actually be mistaken for either of the other species, since its flower heads often have several other types of structures. Thus, it is very important to avoid this goldenrod when seed collecting!