Blackjack (Figure 1) falls under the following taxonomic tree (Bartolome, Villaseñor & Yang, 2013):
Blackjack (Bidens pilosa L.)
Kingdom:Plantae
Subkingdom:Tracheobionta
Phylum:Spermatophyta
Subphylum:Angiospermae
Class:Magnoliopsida
Order:Asterales
Family:Asteraceae
Genus:Bidens
Species:Bidens pilosa