Why this species#
Gentianopsis crinita is a biennial of wet meadows, fens, old fields and roadside seeps across eastern North America. It germinates one year, flowers the next, and dies. There is no long-lived adult stage to buffer a bad year, and the seed bank is short-lived, so population sizes swing hard between years and local extinctions are ordinary rather than exceptional.
That makes it a good species for a question that matters well beyond gentians: what happens to the genetics of a plant that is not rare enough to be a conservation priority, but is patchy, declining in places, and increasingly cut off from its neighbours? Most of what we know about population genetics in fragmented landscapes comes from either very common species or very rare ones. The fringed gentian sits in the middle, where a lot of the flora actually lives.
What we are doing#
We are collecting a small amount of leaf tissue from roughly fifty populations across the range, sequencing it, and using it to ask:
- How are populations related? Where are the deep splits across the range, and do they line up with anything, glacial history, habitat type, or nothing at all?
- How much genetic variation does each population still hold? Small isolated populations are expected to have lost variation. We want to know how much, and whether it tracks current population size or something older.
- Which populations are isolated? Not isolated on a map, but isolated genetically, which is the thing that actually matters for their future.
None of these questions can be answered from one site, or one state. A single field crew could not reach fifty populations in the few weeks they are in flower, in a year when many of them may not appear at all. So we asked the people who already know where the plants are.
Provenance matters, and it is the hard part#
Fringed gentian is a popular species to sow. Seed gets scattered in restorations, in remnants, and sometimes in nature preserves, and the record of it is often lost. A population that was planted from seed collected 50 miles away tells us about a gardener’s choices, not about the species’ history.
So a large part of this project is unglamorous: asking, for every single site, whether anyone has ever added seed or plants to it. Where the answer is yes or unknown, we either dig into the records or leave the site out. Several promising populations have been set aside on exactly this basis. We would rather have forty well-documented populations than sixty of mixed provenance.
Who is involved#
The project is led by the Agrawal and Benning labs in the Department of Ecology and Evolutionary Biology at Cornell University.
The collecting is being done by botanists, preserve managers, heritage-program staff and naturalists across more than twenty states and provinces. Their names will appear here, and on the resulting papers, as the work comes in.
If you know a fringed gentian population and would like to be part of this, we would be glad to hear from you: jbenning@cornell.edu.