MUSTARD FAMILY. Cruciferse. 



A species naturalized from Europe, and 

 low^gra^s " cornmon throughout our range in barren 

 Drabaverna fields and beside the road. The four white 

 White petals are deeply notched ; the small hairy 



March-May lance-shaped and toothed leaves are clus- 

 tered at the base of the flowering-stems. The pods are 

 shorter than their stems, and elliptical. Flower-stems 

 leafless, and smooth above but a trifle hairy below. 

 1-5 inches high. 



Watercress -^ common aquatic plant, much prized 



Radicula for its pungent-tasting young leaves, which 



Nasturtium- are smooth, dark green, or brownish green 

 aquaticum } n spring^ an( i lighter green in summer. 



A r\\-\u Kst ^ ne i ns ig n ifi can t white flowers terminate 

 the branching stems. Leaves compound 

 with 3-9 roundish leaflets. The scientific name is from 

 nasus, nose, and tortus, twisted, in reference to its sting- 

 ing effect upon the nose. Naturalized from Europe. 4-10 

 inches high. In brooks and small streams everywhere, 

 except in the northernmost parts of our range. 



A yellow-flowered species common 

 Marsh Water- 

 cress everywhere, but naturalized from Europe 



Radicula in the seaboard States ; indigenous in the 



pziusiris west. The leaves ornamentally cut, of 



Yellow usually seven segments. Pods oblong, 



May-August , . , 



about equaling the length of the stems. 



1-3 feet high. In wet situations. 



Lake Cress ^ n a( l ua ^ c species, the finely dissected 



Radicula leaves under water, the upper, oblong, 



aquatica slightly toothed leaves above it. The 



White white flowers on slender stems, smaller 



than those of the Horseradish, and in 

 loose clusters. 1-2 feet. N. Vt. to Minn., southwest. 



A coarse species well known for the im- 

 norseradish 



Radicula mensely strong peppery quality of its large 



Armor ada white roots which furnish a favorite spring 



White table relish. The oblong leaves toothed, 



June-August and roug hl y veined, the basal ones large. 

 The small white flowers rather conspicuous. Pods nearly 

 round. Escaped from cultivation, into moist ground 

 everywhere; naturalized from Europe. 20-30 inches 

 high. 



170 



