Wild Flowers East of the Rockies 399 



SOW THISTLE (Sonchus oleraceus) (EURO- 

 PEAN) is still another of the unwelcome weeds that 

 has come across the water and made itself at home 

 here. Unfortunately the government can establish 

 no immigration bureau that can successfully keep 

 out undesirable plant immigrants, for their seeds 

 come over with all kinds of grain and are sown with 

 them. Practically all foreign plants get their start 

 in cultivated fields or as escapes from flower gardens. 

 This species is not a real thistle at all and the name 

 "Sow" is applied rather as a term of derision, signi- 

 fying spurious or worthless. The specific name, Son- 

 chus, is from the Greek signifying hollow, because 

 the stem of this species is hollow. 



The stem is stout, smooth, grooved, hollow and suc- 

 culent; it attains heights of 1 to 6 feet. The leaves 

 are shaped more like those of the dandelion than a 

 thistle, but are armed with soft spikes. The small, 

 thistle-like flower heads are light yellow; they grow 

 in loose clusters, terminating the branches. 



WILD LETTUCE (Lactuca canadensis) is one of 

 the rankest-growing of our native plants. The milky- 

 juiced, branching, smooth stem ranges in height from 

 3 to 10 feet. The leaves are all very angular, cut, 

 toothed and gouged in all manner of forms. Those 

 near the base of the stem are very large, often attain- 

 ing lengths of more than a foot. They become small- 

 er and less deeply lobed as they mount the stem, the 

 upper, small ones being almost entire-edged. The 

 small, yellow-rayed flowers are numerous but unin- 

 teresting. At maturity they are succeeded by silky 

 beards of down, proceeding from the deep-vase-like 

 involucres. 



