June, 1917] The Brassicacece of Ohio 321 



1. Conringia orientalis (L.) Dum. Hare's-ear Mustard. 

 Stem usually simple, 1-3 ft. tall, somewhat succulent; leaves 

 light green, obtuse, | in. long; petals nearly twice as long 

 as the sepals; pods spreading. 



Adventive from Europe, becoming a bad weed, more com- 

 mon in the Northwest. Cuyahoga, Geauga, Lake. 



22. Hesperis (Tourn.) L. Dame's Rocket. 

 Biennial or perennial erect herbs, pubescent with forked 

 hairs, w^ith simple leaves and large purple flowers in racemes. 

 Stigma 2-lobed. Siliques long, slender, dehiscent. Seeds margin- 

 less, globose, in 1 row in each cavity. 



1. Hesperis matronalis L. Dame's Rocket. Stem branched, 

 2-3 ft. tall; leaves lanceolate, serrate, acuminate, lower leaves 

 long petioled, 3-8 in. long, upper leaves smaller, sessile; flowers 

 an inch broad, fragrant, petals spreading; pods linear, 2-4 in. 

 long. 



A native of Europe, escaped from cultivation. Belmont 

 (Laughlin Herbarium), Franklin, Hamilton, Portage. 



23. Arabidopsis (DC.) Schur. Mouse-ear Cress. 

 Annual erect branching herbs, pubescent with forked hairs, 

 with entire or toothed leaves and small white flowers in terminal 

 racemes. Siliques linear, dehiscent. Seeds wingless, in 1 row 

 in each cavity. 



1. Arabidopsis thaliana (L.) Britt. Mouse-ear Cress. 

 Stem slender, hairy at the base, 1-16 in. high; basal leaves 

 rosulate, obovate, entire or toothed, petioled, 1-2 in. long; 

 stem-leaves smaller, few, acute, sessile; flowers small, petals 

 about twice the length of the calyx; pods pointed, spreading. • 



In old fields and rocky places, naturalized from Europe. 

 Ashtabula, Clinton, Lucas, Montgomery. 



24. Barbarea R. Br. Winter-cress. 

 Biennial or perennial erect branching herbs, with angled 

 stems, pinnatifid leaves and yellow flowers in racemes. Stamens 

 6. SiHques linear, 4-angled. Seeds wingless, in 1 row in each 

 cavity. 



1. Lateral leaf-segments 1-4 pairs. 2. 



1. Lateral leaf-segments 4-8 pairs. B. verna. 



2. Pods spreading. B. barbarea. 

 2. Pods appressed. B. stricta. 



