62 UMBELLIFERAE. 



to oblong; ribs prominent, corky, nearly equal, oil-tubes 1-3 in the intervals. 

 Stylopodium depressed. 



S. cicutaefolium Gmel. Stem 2-6 feet high, striate; leaflets 3-8 pairs, 

 linear to lanceolate, sharply serrate, the submerged leaves finely dissected; 

 rays numerous. Sloughs and swamps; July-September; frequent. 



CARUM L. Ours a glabrous biennial or perennial, with pinnatisected 

 leaves, divisions filiform, and small white flowers in terminal compound um- 

 bels. Calyx-teeth minute. Petals inflexed at the apex. Fruit ovate or ob- 

 long, glabrous, slightly compressed. Stylopodium conical. 



C. carui L Caraway. Stem erect, 1-2 feet high, branching; lower leaves 

 long-petioled, the upper sessile or nearly so, bases of the petioles dilated. 

 Introduced, waste places; May-July; Emmet county, reported from Fayette 

 county. 



CICUTA L. Smooth poisonous perennials. Leaves pinnately compound; 

 leaflets serrate. Involucre usually wanting. Involucels of many slender 

 bractlets. Flowers white. Calyx-teeth 5, broad. Fruit subglobose, glabrous, 

 with 5 equal flattish corky ribs; oil-tubes solitary in the intervals. Stylopo- 

 dium depressed. 



C. maculata L. Water Hemlock. Stem 2-6 feet high, spotted or streaked; 

 leaves bipinnate or tripinnate; leaflets lanceolate, mucronately serrate; veins 

 running to the notches; fruit nearly terete. Sloughs and marshes; June- 

 August; common. 



C. bulbifcra L. Stem 1-3 feet high; leaves 2-3 pinnate; leaflets linear, 

 remotely toothed; upper axils bearing clustered bulblets. Swamps; July- 

 September; infrequent; Muscatine, Linn, and Emmet counties. 



CONIUM L. Biennials, with tripinnately dissected leaves, and white flow- 

 ers. Involucre and involucels of narrow bracts. Calyx-teeth obsolete, fruit 

 ovate, compressed; ribs equal, prominent, wavy when immature; oil-tubes 

 wanting. Stylopodium depressed. 



C. maculatum L. Poison Hemlock. Stem 2-6 feet high, spotted, glabrous, 

 striate, sometimes glaucous; roots fusiform, fleshy; petioles very much dilated. 

 Waste places; June-July; Winneshiek and Scott counties. 



CRYPTOTAENIA DC. Glabrous perennials, with 3-foliolate leaves, and 

 white flowers. Involucre and involucels none. Calyx-teeth obsolete. Fruit 

 glabrous, linear-oblong, with 5 obtuse equal ribs; oil-tubes solitary, beneath 

 each rib and in the intervals. Stylopodium slender-conical. 



C. canadensis DC. Stem smooth, 1-3 feet high; leaflets large, pointed, 

 ovate, doubly serrate, often lobed; umbels irregular, unequally few-rayed; 

 pedicels unequal; fruit often curved. Moist woods; June-September; com- 

 mon. (Derlnija canadensis (L.) Kuntze.) 



BERULA Hoffm. A glabrous aquatic or marsh perennial, with simple 

 pinnate leaves, leaflets serrate and variously cut, involucre and involucels of 

 narrow bracts, and terminal umbels of white flowers. Calyx-teeth minute. 

 Fruit glabrous; ribs slender; pericarp thick, corky; oil-tubes numerous. 

 Stylopodium conic; styles short. 



B. angustifolia (L) Mert. & Koch. Stem 6-30 inches high; leaflets 7-19, 

 ovate to linear-oblong, serrate, laciniate, or lobed. Reported from Sioux 

 county. (B. crecta (Huds.) Coville.) 



ChJAEROPfiYLLUM L. Annuals, with ternately decompound leaves, pin- 

 natifid leaflets, and white flowers. Involucre usually none. Involucels of 

 many bractlets. Fruit narrowly oblong to linear, notched at the base, with 



