24. Zizia. Ribs filiform; stylopodium none. Flowers yellow.

25. Carum. Ribs filiform or inconspicuous; stylopodium short-conical. Leaf-segments filiform. Roots tuberous.

26. Cicuta. Ribs flattish, corky, the lateral largest. Marsh perennials, with serrate leaflets, the veins often running to the notches.

27. Ægopodium. Ribs filiform; oil-tubes none; stylopodium conical. Leaves biternate.

[=][=][=][=] Leaves finely dissected; oil-tubes solitary. Very slender annuals.

28. Leptocaulis. Fruit bristly or tuberculate, with rather prominent equal ribs.

29. Discopleura. Dorsal ribs filiform, the lateral very thick and corky.

[++][++] Seed-face concave; fruit ovate, glabrous, with depressed stylopodium, and no oil-tubes.

30. Conium. An introduced biennial, with spotted stems, and large decompound leaves.

[++][++][++] Seed-face concave. Fruit linear-oblong, with conical stylopodium.