Asteraceae (Sunflower family)
Growth Habit: Annual. 2-4 feet tall.
Leaves: Alternate. Triangular or heart-shaped. Rough on both sides.
Flowers: Flower heads are small. Flowering may occur from July to September.
Seeds: Fruits are one inch long, woody, with hooked prickled and two curved spines at the tip. Two seeds that are dark brown in color. Seeds are flattened and have pointed tips.
Other: Native to North America. Burs are irritating to humans and animals. Both seeds and seedlings contain a substance that is toxic to livestock.