Assertion: parsnip's sap | /r/MadeOf | psoralen
Facets:
Source sentences:
text: But the plant secretes an oily sap containing psoralen that causes a severe reaction when it comes in contact with the skin and then is exposed to sunlight, the Iowa Department of Natural Resources reports.
text: Its sap contains psoralen, which causes severe rashes, blisters and discoloration on the skin, especially when the affected area is exposed to sunlight.