36 CRUCIFER^. (MUSTARD FAMILY.) 



1. S. OFFICINALE, Scop. (HEDGE MUSTARD.) Leaves runcinate ; flow- 

 ers very small, pale yellow ; pods close pressed to the stem, awl-shaped, scarcely 

 stalked. (J) Waste places. May -Sept. An unsightly, branched weed, 

 2 -3 high. (Nat. from Eu.) 



2. S. TUALIANUM, Gaud. (MOUSE-EAR CRESS.) Leaves obovate or oblong, 

 entire or barely toothed ; flowers white ; pods linear, somewhat 4-sided, longer 

 than the slender spreading pedicels. @ Old fields and rocks, Massachusetts 

 lo Kentucky, &c. April, May. A span high, slender, branched, hairy at the 

 base. (Nat. from Eu.) 



3. S. canescens, Nutt. (TANSY MUSTARD.) Leaves 2-pinnatifid, the 

 divisions small and toothed ; flowers whitish or yellowish, very small ; pods in 

 long racemes, oblong or rather club-shaped, not longer than the spreading pedi- 

 cels ; seeds irregularly in 2 rows in each cell. Penn. and Ohio to Wiscon- 

 sin, and southward and westward. Slender, 1 high, often hoary-pubescent. 



11. SIN APIS, Tourn. MUSTARD. 



Pod nearly terete, with a stout beak (which is either empty or 1 -seeded) ; the 

 valves 3 -5- (rarely 1-) nerved. Seeds globose, one-rowed. Cotyledons incum- 

 bent, folded around the radicle. Calyx open. Annuals or biennials, with yel- 

 low flowers. Lower leaves lyrate, incised, or pinnatifid. (Greek name St'i/cnri, 

 which is said to come from the Celtic nap, a turnip.) 



1. S. ALBA, L. (WHITE MUSTARD.) Pods bristly, turgid, on spreading 

 pedicels, shorter than the sword-shaped one-seeded beak ; leaves all pinnatifid. 

 (Cult, and adv. from Eu.) 



2. S. ARVENSIS, L. (FIELD MUSTARD. CHARLOCK.) Pods smooth, knot- 

 ty, about thrice the length of the conical 2,-edyed usually empty beak ; upper leaves 

 merely toothed. A noxious weed in cultivated fields, NCAV York and Wiscon- 

 sin. (Adv. from Eu.) 



3. S. NiGRA, L. (BLACK. MUSTARD.) Pods smooth, l-cornered (the valves 

 l-nerved only), oppressed, tipped with a slender persistent style (rather than beak) ; 

 leaves lyrate or lobed, the upper narrow and entire. Fields and waste places. 

 The acrid seeds furnish the mustard of our tables, &c. (Adv. from Eu.) 



12. DRAB A, L. WHITLOW-GRASS. 



Pouch oval, oblong, or even linear, flat ; the valves plane or slightly convex, 

 I - 3-nerved : partition broad. Seeds several or numerous, in 2 rows in each 

 sell, marginless. Cotyledons accumbent. Calyx equal. Filaments not toothed. 

 Low herbs, with entire or toothed leaves, and white or yellow flowers. Pu- 

 bescence mostly stellate. (Name from Spa/3^, acrid, in allusion to the pungency 

 of the leaves.) 



$ 1. DRAB A, DC. Petals undivided. 

 * Perennial, tufted, leafy-stemmed : flowers white : pods twisted when ripe. 



1. I>. ramosissima, Desv. Diffusely much branched (5'- 8' high), 

 pubescent; leaves laciniate-toothed, linear-lanceolate, the lower oblanccolate; ra- 



