April 27 2017: (re)collected on this day

Expect more "recollected on this day" posts.  Last year, we botanists initiated a long term "recollection" project at the Carnegie Museum of Natural History where we are revisiting sites across western Pennsylvania on the same calendar day as former plant collectors to compare current plants to those of our historic specimens.  We are focusing on sites where collections are particularly strong -- southwestern Pennsylvania.  Many of these sites are now state parks, roadsides, or have been developed as residential areas and/or have been transformed by human activities altogether.

Some results from the first year of this project can be found in the new We Are Nature: Living in the Anthropocene exhibition at the museum.  These specimen recollections will grow the plant collection at the museum in a way to maximize future research.  For instance, we can compare phenology (for example, flowering times) and how they might be affected from a century of climate change.  We are also documenting introduced and invasive species which were absent from these sites 20, 50, or 100+ years ago, as well as native species which may no longer be locally present or abundant.  More results to come! 

And, who knows how scientists 20, 50, or 100+ years will use these specimens.

Below is a sampling of some recollections from April 27, 2017 in Fox Chapel, Pennsylvania (near Pittsburgh). Note the striking differences in stages of flowering development between 1900 and 2017.  The specimens on the left were collected by the first curator of botany at the museum, John Shafer.

Bloodroot (Sanguinaria canadensis):  collected 117 years apart

Spring beauty (Claytonia virginica): 117 years apart

Witch hazel (Hammamelis virginiana): 133 years apart

Dutchman's breeches (Dicentra cucullaria): 117 years apart

Spicebush (Lindera benzoin): 117 years apart