There are only a few plants of this, so botanists, please don't collect a specimen.

This keys out to Eupatorium godfreyanum in the Gleason and Cronquist Manual and it matches specimens in the Mid-Atlantic Herbaria database. I worried whether the leaves are truly pinnate, but the veins match those of the herbarium specimens.

https://www.midatlanticherbaria.org/portal/taxa/index.php?taxon=Eupatorium+godfreyanum&formsubmit=Search+Terms

"Dry, open, disturbed sites, edges of deciduous woods; 20-300+ m; Ky., Md., N.J., N.C., Ohio, Va., W.Va. Eupatorium godfreyanum is an apomictic polyploid derivative that includes genomes from E. rotundifolium and E. sessilifolium. Although it is relatively narrow in distribution, it is known to occur in localities where both progenitor species are absent and it seems to be persistent where it occurs."

Plants which are apomictic polyploids produce seeds without fertilization of flowers by pollen.

https://www.frontiersin.org/articles/10.3389/fpls.2019.00358/full

The BONAP distribution map shows it as rare in Lancaster, York, Lebanon, and Dauphin Counties in PA. Also in Fulton Co. farther west. These populations are disjunct from non-rare populations to the south, which are mainly in Virginia. iNaturalist has a number of observations of it in the Durham, NC area.

http://bonap.net/Napa/TaxonMaps/Genus/County/Eupatorium

iNaturalist suggested ID's:

Eupatorium sessilifolium - Upland Boneset
Eupatorium pubescens - Roundleaf Thoroughwort
Eupatorium rotundifolium - Round-leaved Boneset
Eupatorium pilosum - Rough Boneset
Eupatorium altissimum - Tall Boneset

Another possibility is Eupatorium godfreyanum.