Minnesota Plant Life. 



409 



are often filled with the dead bodies of insects. It is probable 

 that the plant is partially carnivorous like the pitcher-plants. 

 The flowering heads are yellow, like small sunflowers. The 

 compass-plant rosinweed produces near the surface of the 

 ground a number of leaves a foot or more long, with very deep 

 lobes running from the margin to near the midrib. These 

 leaves stand upright and arrange themselves with their edges 

 north and south. A third variety, known as the prairie-dock, 

 displays large, long heart-shaped leaves, a foot in length and 

 six inches or more in width at the base. They compose a large, 

 loose rosette and do not 

 stand erect like those of the 

 compass-plant. In each va- 

 riety the flower heads arc 

 yellow, both in the disks and 

 in the rays. The related 

 oxeyes or sunflower herbs, 

 as their name indicates, re- 

 semble sunflowers closely. 



In the coneflow^ers the 

 disk is hemispherical, con- 

 ical or columnar in contour. 

 One variety, the long- 

 headed coneflower, has the 

 disk flowers arranged in a 

 cylindrical, pointed cone, of 

 a brownish color when ma- 

 ture, with a few large yel- 

 low ray flowers at the base. The sunflowers are mostly upright 

 herbs, with heads consisting of numerous tubular disk flowers 

 surrounded by conspicuous yellow rays. The ray flowers con- 

 tain neither stamens nor pistils and are purely for the purpose of 

 attracting insects to the less ornamental stamen- and carpel-bear- 

 ing flowers of the disk. Such a division of labor between the 

 different flowers of the head marks a very high degree of special- 

 ization. In some sunflowers the foliage leaves are opposite 

 while in others they are alternate. Some have sessile leaves, 

 while in others they are stemmed. In some the foliage is 

 smooth, while in others it is rough, and in some the disk 



Fjg. 204. 



Early golden-rod. 

 Brown. 



After Britton and 



