Looking deeper into the data at
GRIN ...
Historically there were five accessions. All of them refer to Calotropsis procera as
small crownflower.
They were collected:
30-Jun-1920. Nyanza, Kenya. (PI 51429 No. 1029)
07-Sep-1921. Syria. (PI 54451)
07-Jan-1927. Georgetown, Gambia. (PI 73507 No. 1153, Collected by Douglas Fairbanks)
15-Feb-1935. Federal District, Venezuela. On road between Caracas and Cabo Blanco. (PI 110905 No. 3067)
Ethiopia. (PI 195920 Guinde)
It's interesting that the 3rd accession was collected by Fairbanks himself! Have you checked at the
Fairchild Tropical Botanic Garden ?