CRUCIFERiE. (MUSTARD FAMILY.) 71 



3. B. (or SinApis) nigra. (Black Mustard.) Pods smooth (\' long), 

 4-cornered (the valves only 1 -nerved), erect on appressed pedicels forming 

 a slender raceme, tipped with a stout persistent style ; seeds dark brown, small- 

 er and more pungent than in the last ; lower leaves with a large terminal lobe 

 and a few small lateral ones. — Fields and waste places, or cultivated. (Adv. 

 from Eu.) 



B. campestris, L., in the form of the Rutabaga and the Turnip, some- 

 times persists a year or two in neglected grounds. 



10. DRAB A, L. Whitlow-Grass. 



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

 the partition broad. Seeds several or numerous, in 2 rows in each cell, margin- 

 less. Cotyledons accumbent. Calyx equal. Filaments not toothed. — Low 

 herbs with entire or toothed leaves, and white or yellow flowers; the pubes- 

 cence often stellate. (Name from dpdfir], acrid, in allusion to the pungency of 

 the leaves.) 



§ 1. DRAB A, DC. Petals not notched nor cleft. 

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



1. D. ramosissima, Desv. Diffusely much branched and forming many 

 radical tufts, perennial (5' -8' high), pubescent; leaves laciniate-toothed, linear- 

 lanceolate, the lower oblanceolate ; racemes corymbosely-branched ; pods hairy, 

 oval-oblong or lanceolate (2" -5 7 long), on slender spreading pedicels, tipped 

 with a long style. — Cliffs, Harper's Ferry, Natural Bridge, &c, Virginia to Ken- 

 tucky River, and southward. April, May. 



2. D. arabisans, Michx. Slightly pubescent, the perennial root bearing 

 rather numerous radical tufts ; flowering stems (6'- 10' high) erect and mostly 

 simple; leaves oblong-lanceolate, linear, or the lower spatulate, sparingly toothed; 

 racemes short, usually simple; pods glabious, oblong-lanceolate (5'- 6' long), 

 acute, on rather short and spreading pedicels, pointed with a shoH but distinct 

 style. — Rocky banks, N. Vermont and New York towards the St. Lawrence, 

 also Akron, Ohio {Clinton), and shores of L. Huron and L. Superior. May, 

 June. — Petals rather large. Too near some forms of the next. 



3. D. ineana, L. Hoary-pubescent, biennial or somewhat perennial, the 

 radical tuft seldom branching ; leaves shorter, raceme more strict, petals smaller, 

 and pods shorter and blunter than in the last, often pubescent, on short erect pedi- 

 ,cels; style very short or none. — Dry rocks, Willoughby Mountain, Vermont, 



Tuckerman, H. Mann. ; also high northward. (Eu.) 



* * Annual or biennial: leafy stems short : flowers white, or in No. 5 yellow: style 

 none. (Leaves oblong or obovate, hairy, sessile.) 



4. D. brachycarpa, Nutt. Low (2' - 4' high), minutely pubescent ; stems 

 leafy to the base of the dense at length elongated raceme ; leaves narrowly ob- 

 long or the lowest ovate (2" -4" long), few toothed or entire; flowers small; 

 pods smooth, narrowly oblong, acutish (2" long), about the length of the ascending or 

 spreading pedicels. — Dry hills, Illinois, Kentucky, Virginia, A. H. Curtiss, and 

 southward. April. — Petals sometimes minute, sometimes none. 



