28 crucifkim;. (mustard family.) 



5. A. Canadensis, L. Stem stout, simple, nearly smooth above ; leaves 

 thin, downy, lanceolate, slightly toothed, sessile by a narrow base, the lowest 

 coarsely or pinnatilid-toothcd ; siliques curved, drooping, on rough pedicels; 

 B eds winged. (A. falcata, Mtchx.) — Dry or rocky places in the upper districts. 

 May and June. — Stems 2°-3° high. Silique 2'-3' long. Flowers white. 

 Petals oblong linear, not twice the length of the hairy calyx. 



G. A. laevigata, DC. Smooth and glaucous ; stem erect ; leaves linear 

 or lanceolate, entire or sparingly toothed, sagittate and clasping at the base ; 

 pedicels short; petals (whitish) narrow, slightly e.xserted ; silique elongated, 

 narrow-linear, recurved-spreading j seed winged. — Rocky places, North Caro- 

 lina. Tennessee, and northward. May. — Stem l°-2° high. Silique 2' -3' 

 long. 



7. SISYMBRIUM, L. Hedge-Mustard. 



Silique linear or oblong, terete or somewhat angled, with 1 -3-nervcd valves. 

 Seeds in a single row in each cell, oblong, marginless. Cotyledons linear-oblong, 

 incumbent — Herbs with simple or pinnately divided leaves. Flowers in ra- 

 cemes, small, white or yellow. 



1. S. canescens, Nutt Pubescent and somewhat hoary ; stem simple or 

 sparingly branched ; leaves bipinnatifid, with small mostly toothed- lobes ; ra- 

 cemes at length elongated ; silique shorter than the spreading pedicel. (Carda- 

 mine ? multifida, DC.) — Waste ground, Florida, northward and westward. 

 March and April. (T — Stem l°-2° high. Flowers small, greenish-white. 



2. S. Thaliana, Gaud. Stem slender, branching, hairy at the base ; leaves 

 hairy, toothed or entire, the lowest obovate or oblanceolate, tufted, the others 

 small and scattered ; siliques linear, erect-spreading, twice as long as the pedi- 

 cels. — Kocks and sterile soil, Georgia and northward. Introduced. March 

 and April. (5) — Stem 4' -8' high. Flowers white. 



3. S. officinale, Scop. Stem tall (2° -3°), branching, and with the run- 

 cinate leaves pubescent; silique subulate, nearly sessile, appresscd to the rachis. 

 — Waste grounds in the upper districts, and northward. Introduced. May- 

 Sept CL — Flowers pale yellow. 



8. WAREA, Nutt. 



Silique linear, flattened, long-stalked, recurved; the valves 1 -nerved. Seeds 

 in a single row in each cell. Cotyledons oblong, flat, incumbent. — Smooth 

 and erect brandling annuals. Leaves entire. Flowers showy, in corymb-like 

 racemes. Petals long-clawed, white or purple. 



1. W. amplexifolia, Nutt. Leaves oval and slightly clasping j petals 

 oval, bright-purple; silique linear. — Sand hills, Florida. September. — Stem 

 l°-2° high. 



2. W. CUneifolia, Nutt. Leaves wedge-lanceolate ; petals obovate, white 

 or tarelj purple; silique narrow-linear. — Sandhills, Florida and Georgia. 

 September. — Stem 1° - 2° high. 



I 



