28 CRUCIFERiE. (mustard FAMILY.) 



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

 thin, downy, liuici'olate, sli|;'htly toothed, sessile hy a luirrow base, the lowest 

 coarsely or pinnatiful-toothcd ; siliqiies curved, droopiiifr, on rou<;h pedicels; 

 seeds winj;ed. (A. falcata, Michx.) — Dry or rocky places in the up])er districts. 

 M.iy and June. — Stems 2° -3° high. Siliquc 2' -3' long. Flowers white. 

 Petals olilong-linear, not twice the length of the hairy calyx. 



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

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

 pedicels short; petals (whitish) narrow, slightly exscrted ; silicjue elongated, 

 narrow-linear, recurved -spread ing ; seed winged. — Koiky places, North Caro- 

 lina, Tennessee, and northward. May. — Stem I°-2° high. Siliquc 2' -3' 

 long. 



7. SISYMBRIUM, L. Hedge-Mustard. 



Siliquc linear or oblong, terete or somewhat angled, with 1 -3-nerved valves. 

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

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

 cemes, small, white or yellow. 



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

 sparingly branclied ; leaves bi])innatitid, with small mostly toothed lobes ; ra- 

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

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

 March and A]m\. (j) — 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 oblanccolate, tiifted, the others 

 small and scattered ; siliqucs linear, erect-spreading, twice as long as tlie pedi- 

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

 and April, g; — Stem 4' - 8' high. Flowers white. 



3. S. oflB.cinale, Scop. Stem tall (2°-.*}°), branching, and with the run- 

 cinatc leaves jiubcscent ; siliquc subulate, nearly sessile, appressed to the rachis. 

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

 Scpt. (X — Flowers pale yellow. 



8. WAREA, Nutt. 



Siliquc linear, flattened, long-stalked, recurved; the valves 1-ncrvcd. Seeds 

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

 and crcct branching annuals. Leaves entire. Flowers showy, in corymb-like 

 racemes. Petals long-clawcd, white or purple. 



1. W. amplexifolia, Xutt. Leaves oval and slightly clasping; petals 

 oval, bright-pur](ii' ; sili<itie linear. — Sand hills, Florida. Septeinl)er. — Stem 

 lo-2° high. 



2. W. CUnoifolia, Xutt. Leaves wcdgc-lanccolatc; petals obovate, white 

 or rarely piirpi'' ; Mli(|iii' niirrow-linear. — Sand hills, Florida and Georgia. 

 Scpt<;ml.(r. — Stem l"-ii° hipii. 



