flying within the US with a cactus in carryon

I'll be flying domestically within the US from a part of the country where cacti are common to one where they aren't. As a small token gift I'd like to bring a small prickly pear cactus from my yard. These cacti are covered in small spines and could possibly be used as a weapon, albeit not a very effective one. I won't be checking any bags so unfortunately it would have to travel in my carryon.

Would it allowed to bring a cactus in my carryon or is it considered a banned item?

I am flying from Colorado to Logan International in Boston. The flight is domestic so I wouldn't go through Customs.