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..
A perennial herb, with decompound leaves, their segments broad, cuneate, and large umbels of whitish-yellow flowers. Involucre and involucels of many narrow bracts. Calyx-teeth very small. Fruit ovate-oblong, somewhat flattened dorsally; primary ribs winged; oil-tubes solitary in the intervals, 2 on the commissural side. [Greek, horse-parsley.]
A monotypic genus of the Old World.
Ligusticum Levisticum L. Sp. Pl. 250. 1753. Levisticum officinale Koch, Nov. Act Nat. Cur.
I21: 101. 1824. Levisticum Levisticum Karst. Deutsch. Fl 844.
Stout, branched, 6° high or less, glabrous, except the puberulent pedicels, the rootstock stout, yellowish. Leaf-segments broadly ovate or oblong, 2'-3' long, often 2' wide, entire and cuneate at the base, sharply and coarsely lobed or toothed above the middle; umbels 2'-3' broad, the rays stout; pedicels short, about 2" long, about as long as the fruits.