How to Photograph Goldenrods
It's goldenrod season, and these glorious plants are attracting a lot of attention! Did you know there are over 30 species of goldenrod (Solidago) in the state? Kentucky's goldenrods range from weedy and common statewide, to globally rare and narrowly endemic. With all that diversity, they can be challenging to identify: a few species are highly distinctive and identifiable from a single photo, but many are very similar, and often one photo doesn't provide enough information to ID them.
My recommendation for getting your unknown goldenrods identified is to make a habit of taking multiple photos. Identifiers are looking for a particular set of characteristics to determine species ID's, so here are 4 photos you should take to give goldenrod gurus the visual information they need:
Photo 1) The Whole Plant
When you're making an effort to take detailed photos of leaves and flowering parts, it can be easy to forget to take a photo that shows the entire plant (or at least as much as you can get in the photo), but this shot is very important, and helps identifiers interpret all the finer details of your other photos in context. Make sure to take this photo straight on while standing a few feet away, rather from an overhead angle or looking directly down at it -- the lower parts of the plant will likely be out of focus or obscured if you are photographing from above.
Whole plant photos are helpful for showing growth habit, and overall size and proportions. This also important for showing the shape of the inflorescence, which are often distinctive to groups of goldenrod species. Is yours broadly pyramidal or cylindrical and upright? Plume-like and arching? Flat-topped to domed? An arching line of small clusters in the leaf axils? Or does the inflorescence have several long slender branches that spread out in all different directions? This shape can be very informative!
S. flexicaulis by fryj, S. caesia by sekistler, and S. nemoralis by cebalrai
S. altissima by ktuttlewheeler, S. erecta by kentuckybarefoot, S. rigida by tararoselittlefield.
Photo 2) Mid-Stem Leaves
The size, shape, hairiness, venation, and toothiness of leaf edges is best photographed on leaves near the middle of the stem. This photo will also show how hairy or smooth the stem is in the middle of the plant -- some species have densely hairy stems, others are smooth with a waxy bloom, and that difference is useful for differentiating between similar species.
S. patula by sekistler, S. sphacelata by emwachter, S. gigantea by qtowery
S. rugosa by sbrockway, S. nemoralis by sbrockway, and S. rigida by lzmorris
Photo 3) Basal Leaves (if present)
Some goldenrod species have a cluster of leaves coming out of the very base of the stem. If your goldenrod has basal leaves (or if you're not sure whether the lowest leaves you're seeing are considered basal leaves) make sure to take a photo of these, since they can be helpfully diagnostic.
S. hispida by abelkinser, S. arguta by hbraunreiter, S. faucibus by devinmrodgers
Photo 4) Flower Profile
While holding the stem or a branch of the inflorescence, snap a photo of a few individual flowers from the side. The size of individual flowering heads and the shape of the phyllaries is often distinctive.
S. buckleyi by cherthollow, S. rigida by cassisaari, S. caesia by weboflifephotography
