This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Erect, mostly pubescent perennial herbs, with ternately compound leaves, and compound umbels of white or pinkish flowers. Bracts of the involucre few and deciduous, or none. Involucels of numerous linear bracts. Calyx-teeth obsolete or small. Petals cuneate, or clawed, those of the outer flowers dilated and obcordate or 2-lobed. Stylopodium thick, conic. Fruit much flattened dorsally, broadly oval, obovate, or orbicular; dorsal and intermediate ribs filiform, the lateral ones broadly winged and the wings nerved near the outer margin; oil-tubes extending only to about the middle of the carpels, conspicuous, 1 in each interval, 2-4 on the commissural side. [Greek, to Hercules.]
About 60 species, natives of the northern hemisphere, only the following in North America.
Type species: Heracleum Sphondylium L.
H. lanatum Michx. Fl. Bor. Am. 1: 166. 1803.
Very stout, tomentose-pubescent, 4°-8° high, the stem ridged, often 2' thick at the base. Leaves petioled, ternately divided, very pubescent beneath, the segments broadly ovate, or orbicular, cordate, stalked, lobed and sharply serrate, rather thin, 3'-6' broad; petioles much inflated; umbels 6-12' broad, 8-30-rayed, the rays stout, 2'-4' long; pedicels 3"-9" long in fruit; fruit broadly oval, or obovate, 4"-6" long, 3"-4 1/2" broad, finely pubescent, emargi-nate at the summit.
Heracleum Sphondỳlium L., of Europe, which is loosely pubescent, with pinnate leaves, has been found in ballast and waste grounds about the seaports.