June, 191 /J The Brassicacece of Ohio 315 



dissected into many very narrow segments; emersed leaves 

 1-3 in. long, oblong, entire or serrate, easily broken off; pods 

 1-6 in. long, with style half as long; pedicels spreading. 

 Detached leaves said to produce new plants. 



Indigenous but local in lakes and slow streams. Coshocton, 

 Licking, Lucas, Madison, Perry. 



10. Sisymbrium (Tourn.) L. Water-cress. 



Perennial glabrous aquatic herbs, with pinnate leaves and 

 small white flowers in short erect terminal racemes. Siliques 

 broadly linear on slender pedicels, style stout. Seeds numerous, 

 in 2 rows in each cavity, wingless. A monotypic genus of the 

 Old World. 



1. Sisymbrium nasturtium-aquaticum L. True Water- 

 cress. Stems creeping and rooting at the nodes, fleshy; leaflets 

 3-11, roundish, entire or notched, the terminal one largest; 

 petals twice as long as the sepals; pods \-l\ in. long, ascending 

 on spreading pedicels. 



Originally cultivated, but now naturalized in shallow 

 brooks and spring drains. Rather general. 



11. Radicula Hill. Yellow-cress. 

 Branching herbs with lyrate or deeply pinnatifid leaves and 

 small yellow flowers in lateral and terminal racemes. Siliques 

 short, terete dehiscent. Seeds numerous, turgid, marginless, 

 in 2 irregular rows in each cavity. 



1. Stems creeping, leaves pinnatifid. R. sylvestris. 



1. Stems erect, leaves lyrate. 2. 



2. Glabrous, pods linear to ellipsoid. R. paluslris. 

 2. Hirsute, pods globose. R. hispida. 



1. Radicula hispida (Desv.) Britt. Hispid Yellow-cress. 

 Resembles R. palustris, but is stouter, taller, 4 ft. high, with 

 lower leaves 10 in. long; hirsute with spreading hairs, especially 

 at the base of the plant; pods globose or a little longer than 

 thick. 



Annual or biennial in wet places, more common eastward. 

 Introduced from Europe. Cuyahoga, Erie, Huron, Logan, 

 Monroe, Ottawa, Shelby, Summit. 



2. Radicula palustris (L.) Moench. Marsh Yellow-cress. 

 Stems erect, bushy, glabrous, 1-3| ft. high, from fibrous roots; 

 leaves 3-7 in. long, lyrate-pinnatified or the upper ones smaller, 

 laciniate, the lobes oblong and toothed; pods short, linear- 

 oblong. 



