Giant horsetail, often referred to as giant horsetail, stands out with hollow, bamboo-like stems reaching up to 5 meters tall. Its lush, reed-like appearance is enhanced by whorled branches and a lack of true leaves, indicative of its prehistoric ancestry. Thriving in wet environments, the grooved stems and segmented architecture aid giant horsetail in spreading aggressively, often forming dense colonies that hark back to the age of dinosaurs.