Simple:
* The thistle bloomed with vibrant purple flowers.
* The farmer cleared the field of thistles.
* The thistle has sharp spines that can cause discomfort.
Figurative:
* The thistles of doubt grew in his mind. (metaphor)
* The prickly thistle represented the difficulties he faced. (symbolism)
* He felt like a thistle amidst a field of roses, different and prickly. (simile)
Specific:
* The Scottish thistle is a national symbol of Scotland.
* The thistle was used in traditional medicine to treat various ailments.
* The thistle is an important food source for certain insects.
Humorous:
* The thistle was so prickly, it could have stopped a tank.
* He accidentally sat on a thistle, and it was quite the prickly situation.
The best way to use "thistle" in a sentence depends on the context and the message you want to convey.