Arctium tomentosum
 
Cotton Burdock

Mature Flower Head Side

Regina
21-July-2017

Note the involucre is densely arachnoid-tomentose and the bracts are hooked-spiny tipped.

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Tomentosum: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species. 
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involucre densely arachnoid-tomentose; NOT [involucre glabrous, sometimes slightly woolly]

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corolla glandular