CRUCIFEILE. (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 lohe 

 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 Spa/Sq, acrid, in allusion to the pungency of 

 the leaves.) 



1. DRABA, 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" 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 glabrous, oblong-lanceolate (5'- 6' long), 

 acute, on rather short and spreading pedicels, pointed with a short 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. incana, 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. 



