Calyx-teeth obsolete. Fruit linear, notched at base, long-beaked, glabrous, without ribs (but beak ribbed); oil-tubes none, stylopodium conical, seed-face sulcate.--Resembling _Chærophyllum_ in vegetative characters. (The ancient Roman name.) A. CEREFÒLIUM, Hoffm. Mature fruit smooth and shining. (Chærophyllum sativum, _L._)--Naturalized in E. Penn. (From Eu.) 20. BUPLEÙRUM, L. THOROUGH-WAX. Calyx-teeth obsolete. Fruit oblong, with very slender ribs, no oil-tubes, depressed stylopodium, and seed-face somewhat concave.--Smooth annual, with ovate perfoliate entire leaves, no involucre, involucels of 5 very conspicuous ovate mucronate bractlets, and yellow flowers. (Name from βοῦς, _an ox_, and πλευρόν, _a rib_.) B. ROTUNDIFÒLIUM, L., is very common in fields and cultivated ground, N. Y. to N. C., west to Mo. and Ark. (Nat. from Eu.) 21. CRYPTOTÆ̀NIA, DC. HONEWORT. Calyx-teeth obsolete. Fruit linear-oblong, glabrous, with obtuse equal ribs; oil-tubes solitary in the intervals and beneath each rib; stylopodium slender-conical; seed-face plane.--A glabrous perennial, with thin 3-foliolate leaves, no involucre, involucels of minute bractlets or none, and white flowers. (Name from κρυπτός, _hidden_, and ταινία, _a fillet_, referring to the concealed oil-tubes.) 1. C. Canadénsis, DC. Plant 1--3° high; leaflets large, ovate (2--4´ long), pointed, doubly serrate, often lobed; umbels irregular and unequally few-rayed; pedicels very unequal; fruit 2--3´´ long, often becoming curved.--N. Brunswick to Ga., west to Minn., E. Kan., and Tex. June--Sept. 22. SÌUM, Tourn. WATER PARSNIP. Calyx-teeth minute. Fruit ovate to oblong, glabrous, with prominent corky nearly equal ribs; oil-tubes 1--3 in the intervals; stylopodium depressed; seed-face plane.--Smooth perennials, growing in water or wet places, with pinnate leaves and serrate or pinnatifid leaflets, involucre and involucels of numerous narrow bracts, and white flowers. (From σίον, the Greek name of some marsh plant.) 1. S. cicutæfòlium, Gmelin. _Stout_, 2--6° high; _leaflets 3--8 pairs_, linear to lanceolate, sharply serrate and mostly acuminate, _2--5´ long_ (lower leaves sometimes submersed and finely dissected, as in the next); _fruit 1½´´ long_, with prominent ribs. (S. lineare, _Michx._)--Throughout N. America. 2. S. Carsònii, Durand. _Weak_, 1--2° high; _leaflets 1--3 pairs_, linear, sharply serrate, _1--2´ long; when submersed or floating, very thin, ovate to oblong, usually laciniately toothed or dissected_, the leaf sometimes reduced to the terminal leaflet; _fruit about 1´´ long_.--Mass., R. I., Conn., and Penn. 23. BÉRULA, Koch.