236 FAMILIES OF FLOWERING PLANTS 
Fic. 204. Monkey-Flower (Mimulus ringens). After Britton and Brown, 
Ill. 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 difficult 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 known 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 itis a valuable heart stimulant. The genus Scrophularia, 
type of the family, derives its name from the property which the roots 
were supposed to possess for curing scrofula. Huphrasia, 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. 
