CABBAGE FAMILY 



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petals equal, obovate ; pod rounded, flat, notched, valves boat- 

 shaped, winged ; seeds numerous. (Name, the old Greek name 

 of the genus, connected with thlao^ I flatten.) 



I. T. arvense (Mithridate Mustard, Penny Cress). — Stem 

 slender, erect, a foot high ; catilme leaves oblong, sagittate, 

 toothed ; floivers much smaller than the pods, in a lengthening 

 raceme ; pods round, flat, with very broad wings, and a deep 



thlAspi arvense {Penny Cress). 



notch, h. — I in. across. — Fields ; frequent. It derives its popular 

 names from the resemblance of its seed-vessels in size and shape 

 to silver pennies, and from having formerly been used in a medi- 

 cine known as the Mithridate confection. — Fl. all the summer. 

 Annual. 



2. T. pei'folidtuvi (Perfoliate Penny Cress). — A smaller, much- 

 branched species ; sfe??i-leaves sessile, oblong, heart-shaped at the 

 base, amplexicaul, but not truly perfoliate ; flowers minute ; pod 



