490 



Cruciferae 



Cakile 



Jan. 



Feb. 

 Mar. 

 Apr. 

 May 



June 



July 



Aug 



Sept 



Oct 



Nov 



Dec 



50 



Map 1002 



Thlaspi perforatum L. 



2. Sisymbrium altissimum L. (Norta altissima (L.) Britt.) Tumble 

 Mustard. Map 1005. This is a weed generally of very sandy soil and is 

 found most often in sandy ballast along railroads. It is also found along 

 roadsides and in waste places and fallow fields where it is sometimes 

 abundant, especially in the sandy area of the northwestern part of the 

 state, where it sometimes covers acres. 



Nat. of Eu. ; N. S. to Ont. and B. C, southw. to Va., Mo., Colo., and Oreg. 



3. Sisymbrium Thalianum (L.) J. Gay. (Arabidopsis Thailand (L.) 

 Britt.) Thale-cress. Map 1006. A weed of sandy soil usually found in 

 pastures and fallow and cultivated fields. Sometimes it is common where 

 it is found, especially in sandy, fallow cornfields. Its distribution in the 

 state suggests that it prefers a sandy and slightly acid soil. 



Nat. of Eurasia; Mass., Ont. to Minn., southw. to Ga., Mo., Ark., and 

 Utah. 



2920. CAKILE [Tourn.] Mill. 



1. Cakile edentula (Bigel.) Hook. var. lacustris Fern. (Rhodora 24: 

 23. 1922.) Map 1007. This plant is restricted to the beach area of Lake 

 Michigan. It was formerly frequent along the beach but at present much 

 of the beach area is within city limits or is used by children as play 

 grounds during the summer months. The plant, consequently, has become 

 very rare and in time will probably become extinct. 



Beaches of Lakes Ontario, Erie, Huron, and Michigan. 



2946. DIPLOTAXIS DC. 



See excluded species no. 257, p. 1051. 



2947. ERUCASTRUM Presl. 

 See excluded species no. 258, p. 1051. 



