Arizona Caltrop is a sprawling annual wildflower that grows along the ground with runners spreading about three feet across. The flowers are bright yellow-orange with red centers. Flowers often close at nightfall. Caltrop thrives on roadsides, plains and desert slopes below 5000 feet in elevation. From the distance large masses of them appear very similar to Mexican Gold Poppy, but Caltrop has 5 petals instead of 4 and blooms July through October, considerably later than the poppy.