Cyclospermum leptophyllum (Pers.) Sprague ex Britton & P. Wilson

Cyclospermum leptophyllum (Pers.) Sprague ex Britton & P. Wilson. Cyclospermum leptophyllum is a species of plant in the family Apiaceae known by the common names marsh parsley, slender celery and fir-leaved celery. This is a plant found worldwide at warm temperate to tropical latitudes and is considered a noxious weed in many areas. It is a taprooted branching herb reaching just over half a meter in height at maximum. It has threadlike green leaves a few centimeters long and small umbels of spherical flowers. Host plant for Eastern Black Swallowtail butterflies.