1906.] 



Some Common Thistles. 



707 



and drops to the ground close to the plant, the pappus floating 

 away without its load. Most of the thistle down seen floating 

 on windy days bears no seed. The spear thistle is very common 

 on roadsides, and in pastures and meadows on almost all kinds 

 of soil throughout the country. 



2. The Welted Thestle {Cirduus crispus, L.) is an annual 

 or biennial plant, not so commonly distributed as the preceding 

 one and gives little trouble to the farmer. The tap-root is 



Fig. 2.— Marsh Thistle {Cnicus faluslris, Hoffm.). 



smaller and the stems more slender than those of the spear 

 thistle. The stem is erect, about 1 ft. to 3 ft. high, winged and 

 covered with fine spines. The leaves and involucre are also 

 covered with spines. The flower-heads are roundish, clustered 

 together at the end of the branches, and bear purplish-crimson 

 flowers. The seeds germinate very readily, and the young 

 plants somewhat resemble those of the spear thistle. 



3. The Marsh Thistle {Cnicus pa lustris, Hoffm.) is one of 

 the commonest species, and is met with all through the country 



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