This section is from the book "Harper's Guide To Wild Flowers", by Caroline A. Creevey. Also available from Amazon: Harper's Guide To Wild Flowers.
Family, Parsley. This species has tuber-bearing roots which are poisonous. Its umbels of white flowers appear in August. It is from 2 to 5 feet tall, with pinnate leaves, once cut. Leaflets, 3 to 9. An involucre of fine bracts lies under the umbel, and smaller bracts underlie the secondary umbellets.
A coarse plant of swamps and low grounds. Probably its parts are all more or less poisonous. Found in all the Eastern States.
 
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