In poetry, a thistle often represents challenges or painful experiences due to its prickly nature. In Rose Hartwick Thorpe's poem "How to Be Happy," the thistle serves as a metaphor for negative thoughts and emotions that can sting and trouble the mind. The poet advises to "keep the blooms, destroy the thistles," suggesting that one should focus on positive aspects of life while eliminating sources of distress.

Thistles have been historically associated with various cultural meanings, often symbolizing strength and protection due to their hardy nature. In literature, they can signify both the beauty and pain of life, making them a versatile symbol. Related terms include "thorn" and "briar," which also evoke themes of struggle and resilience. The use of thistles in poetry can serve as a reminder to focus on the positive while acknowledging the presence of difficulties. The word "thistle" is derived from the Old English "thistel," highlighting its long-standing presence in language and literature.