1. C. Canadénse, Torr. & Gray. Leaflets pinnatifid; wings nearly as broad as the seed; oil-tubes 2--3 in the intervals, sometimes 1 or 4.--Swamps and cold cliffs, from Maine to Minn., southward to N. C. (in the higher mountains), Ind., Ill., and Mo. Aug.--Oct. 5. TIEDEMÁNNIA, DC. Calyx-teeth evident. Fruit ovate to obovate, flattened dorsally; dorsal ribs filiform, the lateral broadly winged, closely contiguous and strongly nerved next to the body (giving the appearance of 5 dorsal ribs); oil-tubes solitary in the intervals, 2--6 on the commissure; stylopodium short, thick-conical.--Glabrous erect aquatic herbs, with leaves reduced to petioles or of few narrow leaflets; involucre and involucels present, and flowers white. (Dedicated to the anatomist _Prof. Tiedemann_, of Heidelberg.) 1. T. teretifòlia, DC. Stem hollow, 2--6° high; _leaves reduced to cylindrical hollow pointed nodose petioles_; oil-tubes filling the intervals.--Ponds and swamps, Del. to Fla., and west to La. Aug., Sept. 2. T. rígida, Coult. & Rose. (COWBANE.) Stem 2--5° high; _leaves simply pinnate_, with 3--9 linear to lanceolate entire or remotely toothed leaflets; oil-tubes mostly small. (Archemora rigida, _DC._)--Swamps, N. Y. to Minn., south to the Gulf. Aug. Poisonous; roots tuberiferous. 6. HERACLÈUM, L. COW-PARSNIP. Calyx-teeth minute. Fruit broadly oval or obovate, like Pastinaca, but with a thick conical stylopodium, and the conspicuous obclavate oil-tubes extending scarcely below the middle.--Tall stout perennial, with large ternately compound leaves, broad umbels, deciduous involucre, and many-leaved involucels, white flowers, and obcordate petals, the outer ones commonly larger and 2-cleft. (Dedicated to _Hercules_.) 1. H. lanàtum, Michx. Woolly; stem grooved, 4--8° high; leaflets broad, irregularly cut-toothed.--Wet ground, Newf. to the Pacific, and southward to N. C., Ky., and Kan. June. 7. PASTINÀCA, L. PARSNIP. Calyx-teeth obsolete. Fruit oval, very much flattened dorsally; dorsal ribs filiform, the lateral extended into broad wings, which are strongly nerved toward the outer margin; oil-tubes small, solitary in the intervals, 2--4 on the commissure; stylopodium depressed.--Tall stout glabrous biennial, with pinnately compound leaves, mostly no involucre or involucels, and yellow flowers. (The Latin name, from _pastus_, food.) P. SATÌVA, L. Stem grooved; leaflets ovate to oblong, cut-toothed.--Introduced everywhere. (Adv. from Eu.) 8. POLYTÆ̀NIA, DC.