21. Cryptotænia. Ribs obtuse, equal; fruit linear-oblong. [=][=] Leaves once pinnate; stylopodium depressed; oil-tubes numerous. Aquatic perennials. 22. Sium. Fruit ovate to oblong; ribs prominent, corky, nearly equal. 23. Berula. Fruit nearly globose; ribs inconspicuous; pericarp thick and corky. [=][=][=] Leaves decompound. Oil-tubes solitary (none in n. 27). Perennials. 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. 31. Chærophyllum. Fruit glabrous, with small mostly solitary oil-tubes. 32. Osmorrhiza. Fruit bristly, with oil-tubes obsolete. [+][+][+] Carpels (as well as fruit) strongly flattened laterally. [++] Seed lunate, deeply sulcate on the face; umbels compound, leafy-bracted. 33. Erigenia. Fruit nearly orbicular, with numerous oil-tubes. Low, nearly acaulescent from a deep-seated tuber. Leaves ternately decompound. [++][++] Seed straight, not sulcate; umbels simple. 34. Hydrocotyle. Fruit more or less orbicular, with no oil-tubes. Low perennials, in or near water, with creeping stems, and peltate or reniform leaves. [*][*][*][*] Fruit obovoid or globose, densely prickly or scaly. 35. Eryngium. Flowers sessile in dense bracteate heads, white or blue. Leaves mostly rigid and more or less spinose. 36. Sanicula. Flowers in irregularly compound few-rayed umbels, yellow. Leaves palmate. 1. DAÙCUS, Tourn. CARROT. Calyx-teeth obsolete. Fruit oblong, flattened dorsally; stylopodium depressed; carpel with 5 slender bristly primary ribs and 4 winged secondary ones, each of the latter bearing a single row of barbed prickles; oil-tubes solitary under the secondary ribs, two on the commissural side; seed-face somewhat concave or almost flat.--Bristly annuals or biennials, with pinnately decompound leaves, foliaceous and cleft involucral bracts, and white flowers in compound umbels which become strongly concave. (The ancient Greek name.) D. CARÒTA, L. Biennial; stem bristly; ultimate leaf-segments lanceolate and cuspidate; rays numerous.--Naturalized everywhere, from Eu. 2. CAUCÀLIS, L.