blue thistle

Từ điển WordNet v3.1 - WordNet Dictionary

noun

a coarse prickly European weed with spikes of blue flowers;
naturalized in United States
• Syn:
blueweed, blue devil, viper's bugloss, Echium vulgare
• Hypernyms:
herb, herbaceous plant
• Member Holonyms:
Echium, genus Echium