236 



FAMILIES OF FLOWEKING PLANTS 



Fig. 204. Monkey-Flower {Mimultis ringens). After Britton and Brown, 



111. Fl. Northeast U. S. 



ous features of the fall landscape, particularly in rather dry situations. 

 The false foxglove {Dasystoma) was formerly included in the genus 

 Gerardia, but is distinguished by its yellow flowers. There are several 

 peculiar features about the Gerardias and their allies. In the first place 

 they are all partial root parasites, deriving a portion of their sustenance 

 from the roots of other plants, a fact that renders it diflicult to trans- 

 plant them. In addition they have the singular property of turning 

 completely black during the ordinary process of drying. 



Another large genus of the same group is Veronica, which includes 

 the common speedwells, low herbs with flowers of different colors, some 

 found as weeds in the lawn and meadow, others growing along brook 

 sides, whence they are called "brooklime". The louseworts {Pedicularis) 

 are most abundant in arctic and alpine regions. They have a peculiarly 

 shaped corolla knowTi as galeate, from the resemblance of its upper lobe 

 to a helmet. (See Fig. 205.) 



A number of the plants belonging to the Scrophulariaceae possess 

 strongly marked medicinal properties. Thus the European foxglove 

 {Digitalis) contains an intensely poisonous alkaloid called digitalin, but 

 in small doses it is a valuable heart stimulant. The genus Scrophidaria, 

 type of the family, derives its name from the property which the roots 

 were supposed to possess for curing scrofula. Euphrasia, a large Old 

 World genus, is known as eye-bright, from its use, both externally and 

 internally, in complaints of the eyes. 



Mention has already been made of most of the ornamental genera, 

 but the handsome tree Paulownia imperialis should not be overlooked. 



