402 



Minnesota Plant Life. 



marsh-elders, chicories, hawkweeds, rattlesnake-roots, wild let- 

 tuces, dandelions, sow-thistles and corn-flowers. In some of 

 these groups there are a large number of Minnesota species. 

 For example, there are six sorts of blazing-stars, six thorough- 

 w'orts, nine or ten fleabanes, thirty goldenrods and about forty 

 asters, besides eleven or twelve wormwoods or sage-brushes, 

 ten or eleven thistles and fifteen sunflowers. 



The composite family may for convenience be divided into 

 three sub-families, the dandelions, the ragweeds and the sun- 

 flowers. To the dandelion familv about thirtv Minnesota 



l-'ic;. 195. l)an<leli<jiis in fruit. After pliotoj^ra])!! by Williams. 



species belong. The characters by which they are classified are 

 minute and it is not possible to go into them in detail. A few 

 of the common forms may, however, be described. 



Dandelions and their relatives. The dandelion is known by 

 its broad flat head of yellow flowers, becoming closed in the 

 early stages of fruiting. In later stages the head opens again 

 and the disk of the flower-cluster becomes conve.x. On this 

 the little spindle-shaped nutlets are situated. Above each 

 nutlet the calyx is prolonged into a rigid thread at the end 

 of which the pappus-hairs diverge in an umbrella-shaped 

 circle. 



