napiumA genus of dicotyledonous plants, type of the family Apiaceæ. They are erect or prostrate glabrous herbs with compound leaves and umbels of white flowers. They are distinguished by the laterally flattened fruit and by the solitary oil-tubes in the intervals between the usually prominent ribs of the carpels. The genus includes about 20 species, natives of the eastern hemisphere, with the exception of A. Ammi, which occurs from North Carolina to Florida and Mexico and extends into South America. Two or three introduced species occur locally in the eastern United States and in California. For A. graveolens see celery, marsh-parsley, 1, and smallage.
I spent a whole moon extracting it from the wild apium, and one drop of it will kill like a lightning flash.