340 



COMMON WEEDS 



EQUISETACE^: 



Horse-tails. All the representatives of this order are 

 adapted for life in wet places. One species, Equisetum 



limosum 

 monly 

 about 2 



is com- 



FIG. 



L, 



met with in 

 or 3 feet of 

 water along the edges 

 of lakes and in ditches. 

 The smooth stems grow 

 from i to 3 feet high, 

 sometimes with short, 

 simple branches in 

 whorls. The terminal 

 spore-bearing spike or 

 cone is short and blunt. 



CHARACE^E 



Various species of 

 Stoneworts (Cham and 

 Nitelld) are lowly bo- 

 tanical forms with a 

 complicated floral 

 structure. They may 

 have simple or 

 branched stems up to 

 i foot long, according 

 to species. Cylindrical 

 branches in whorls are 

 produced at the nodes 

 (Fig. 99). The Stoneworts grow in brackish or fresh 

 water, and are attached to the mud at the bottom, 

 frequently covering large areas with vegetation. They 

 are not usually troublesome. 



j. Stonewort (Chara vulgaris L.), nat. size, 

 with reproductive organs magnified. 



