CANADA THISTLE 



" The thistle is an idealist among plants. Its dreams would 

 be worth recording. When its season of bloom is past, its leaf 

 lances rusted and broken — when seemingly its fortunes are at 

 the lowest ebb — then look out for the shining fleets of its seeds. 

 Through all the fine autumn weather these cruise about, above 

 the fields, over the village streets, even entering the houses 

 through doors and windows. On goes the winged hope of the 

 thistle, flashing white in the sunshine, but dark in the shadow." 



CANADA THISTLE. CREEPING THISTLE 



Cdrduus arvinsis 



A perennial, dioecious plant. The worst pest of all the 

 Thistles because of its creeping roots which make it difli- 

 cult to eradicate. Found in cultivated fields, on road- 

 sides, and in pastures. Naturalized from Europe. June- 

 September. 



Rootstock. — Deep-growing, horizontal, and creeping, and 

 so forming patches and colonies. 



Stem. — Woody, slender, branched above, one to three 

 feet high. 



Leaves. — Alternate, sessile and slightly clasping, oblong- 

 lanceolate, deeply cut into very prickly lobed or dentate 

 segments; basal leaves sometimes petioled. 



Flower-heads. — Discoid-composite, that is, with no ray- 

 florets. Many borne in loose, petioled clusters at the tips 

 of the branches, purple-pink, rarely white. Flower-heads 

 either staminate or pistillate. Pistillate heads oblong, 

 bell-shaped, constricted at the neck; styles pink-purple 

 and projecting, conspicuous, giving a fluffy look to the 

 flower-head. Bracts of the involucre pressed close and 

 each tipped with a tiny hook. Staminate heads globose, 

 corollas projecting. As the seeds mature the pappus be- 

 comes long, silvery, conspicuous. Many heads mature 

 pappus, but no fertile seeds. 



Fertilized by many insects. Nectar-bearing. 

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