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..
Stout and tall maritime perennials, with large 2-3-ternate leaves, inflated petioles, and compound umbels of greenish white flowers. Involucre of a few linear deciduous bracts, or none. Involucels of numerous linear bracts. Calyx-teeth obsolete. Petals with an inflexed apex. Stylopodium depressed. Fruit oblong to subglobose, scarcely flattened; dorsal and intermediate ribs prominent, corky-thickened, the lateral ones slightly broader, acute but not winged; oil-tubes solitary in the intervals, 1-2 under each rib and 2-4 on the commissural side. Seed loose in the pericarp, its face flat or slightly concave. [Greek, hollow-ribbed.]
Four or five species of North America and Asia. Type species: Coelopleurum GmÚlini (DC.) Ledeb.
Angelica Archangelica Schrank, Denks. Regens. Bot.
622. 1840. Ligusticum actaeifolium Michx. Fl. Bor. Am. 1: 166.
S. Nat. Herb. 7: 142. 1900.
Stout, branching, 2°-3° high, glabrous below, the umbels and upper part of the stem puberulent. Lower leaves large, 2-3-ternate, the segments thin, ovate, acute or acuminate, sharply and irregularly dentate and incised, 1 1/2'-2 1/2' long; umbels 3-5' broad, 10-25-rayed; rays 1-2' long; pedicels slender, 3"-6" long; fruit 2 1/2"-3 1/2" long, the lateral ribs scarcely stronger than the others.
Sea-coast, Greenland to Massachusetts, and on the lower St. Lawrence river. Summer. Referred in our first edition to C. Gmelini (DC.) Ledeb. of eastern Asia and Alaska, the type of the genus.