It’s been an education, if frustrating. My latest challenge has been to identify this pretty pink thing.
Unable to tell just from pictures, I printed a few pages from both the Weakley Flora and eFloras and hit the trail, intending to key it out in situ. It keyed out to Persicaria densiflora.
However, some authorities do not currently recognize P. densiflora as a species; they lump it with P. glabra.
A few things to consider…
from “The case for recognizing both Persicaria amphibia and Persicaria coccinea in North America” on iNaturalist.org:
…discussions of Persicaria are complicated by two and a half centuries of back and forth generic lumping and splitting…there now exist an inordinate number of synonyms for every species, sometimes numbering in the hundreds.
It’s also worth noting that every single characteristic matches the description of scarlet smartweed (aka P. coccinea) on Illinois Wildflowers.
Of course, it would appear that just like P. densiflora, P. coccinea is no longer an accepted name; ITIS lists it as a synonym of P. amphibia.
So the flower pictured here could be Persicaria glabra (smooth smartweed), but is more likely Persicaria amphibia (water smartweed)… until botanists and taxonomists recognize the validity of Persicaria coccinea.