76 



WEED FLOEA OP IOWA 



Fig. 41. Curled Dock (Bumex orispus). Roadsides, meadows, clover fields, etc. 

 (Photographed by Charlotte M. King.) 



Clark and Fletcher suggest the following treatment : ' ' Sow clean 

 seed. The prevalence of dock in meadows is due to sowing con- 

 taminated grass and clover seeds. Land worked under a short rota^ 

 tion of crops is never badly infested with docks. When the soil is 

 soft lafter continued raia, they can be pulled from meadows and 

 pastures. Pull or cut and destroy all seed-bearing plants before 

 harvesting a clover seed crop. A handful of salt placed on the 

 crown of docks, after cutting in dry hot weather, will extract the 

 moisture and destroy the root; this is a remedy sometimes used in 

 lawns and pastures when the soil is too hard and dry to permit 

 pulling them. " 



Smooth Dock {Bumex altissimus Wood.). 



Description. — ^A tall, smooth, perennial; leaves pale, ovate, or 

 oblong-lanceolate, thiekish ; flowers in paniculate spikelike racemes, 

 in crowded whorls, nodding pedicels, shorter than the fruiting calyx; 

 valves broadly ovate or obscurely heart-shaped, one with a conspicu- 

 ous pale grain ; aehene triangular, pale. 



Distribution.— Common in the northern states and abundant in 

 low grounds and highways, also in pastures throughout Iowa. 



