From the thorny red rose that draws Laurie's blood when he tries to pick it to the simple orange blossoms that Meg wears on her wedding day, flowers play a constant but subtle symbolic role in Little Women. Luckily, Alcott is rarely too subtle to explain what they mean in her narrator's voice. When Laurie is forced to pick smaller, daintier flowers that are lower down, you don't have to wonder whether this means switching his affections from Jo to Amy – his narrated thoughts make it explicit. When Meg chooses simple, easily obtainable flowers to adorn herself for her wedding, you don't have to theorize that she's emphasizing her homely simplicity. The narrator says so. Thanks, narrator.
Flowers also remind us of the class differences between different families – the Laurences are wealthy enough to have their own greenhouse and grow exotic flowers that they frequently give to the neighboring Marches. But flowers also suggest poverty, such as when Amy uses flowers instead of jewelry to accessorize for a ball.