52 Spring Flora of Ohio. 



b. Pod elongated, somewhat 4-sided, valves nerved: lower leaves 



lyrate Barbai-ea. 3 



b. Not as above e' . 



c. Flowers purplish, stem-leaves auricled, pods 1-1!2 in- long lodanthus. 4 



c. Flowers white or yellow, leaves pinnate, pinnatifid or ver\^ large 

 and crenate. pod oblong-linear to globular, terete or nearly so, 

 seeds in two rows in each cell Roripa. 5 



c. Flowers white or purple, stems leaf\% leaves simple or pinnate, pod 



linear, flattened, seeds in a single row in each cell Ca>damine. 6 



c. Pod, etc.. like the last: stem simple, leafless below, bearing 2 or o 

 petioled compound leaves above the middle : flowers large, white 

 or purple, in corymbs or short racemes Dentaria. 7 



c. Not as above d . 



d. Pod obcordate-triaugular. flowers small, white Bursa. 8 



d. Pod oval, oblong, or linear, flat ; plants low Draba. 9 



d. Pod long-linear, flattened : valves l-nerved or veiny f . 



e. lyeaves pinnate, pinnatifid, or very large and crenate c, above . 



e. Leaves 2-pinnatifid, the divisions small and toothed Descni-ainia. 10 



e. Leaves not as above f . 



f. Pod somewhat 4-sided, leaves obovate or oblong, not clasp- 

 ing Stenophragnia. 11 



f. Pod flattened, leaves simple or compound, often clasping at \i2.'s>&.A>abis. 12 



1. Genus LE-PID'-I-UM. — Pods roundish, notched at the top, much 

 flattened contrary to the narrow partition, the valves keeled; flowers 

 small, white or greenish. 



A. Leaves all with a lapeihig base. 



Le-pid'-i-um vir-gin'-i-cum L. Pepper-grass. — Pod marginless or ob- 

 scurely margined at the top ; petals present. 



Le-pid'-i-um in-ter-me'-di-um Gr. Pepper-grass. — Pod minutely wing- 

 margined at the top ; petals usually mintite or wanting. 



Le-pid'-i-um ru-der-a'-le L. Pepper-grass. — Pods smaller, oval; petals 

 always wanting ; plant more diffuse. 



A. Stem-leai'es 7viih a sagillate base. 



Le-pid'-i-um cam-pes'-tre (L.) Gr. Pepper-grass. — Minutely soft- 

 downy; pods ovate, winged. 



2. Genus SIS-YIVl'-BRI-UIVI.— Pods terete, upright and close-pressed 

 to the stem, flowers ver\- small, pale yellow. 



Sis-ym-bri-um of-fic-i-na'-le (L.) Scop. Hedge Mustard.— Very branch- 

 ing, 2-3 feet high ; leaves runcinate. 



