The seagrass community of South Florida is the largest seagrass meadow in the world covering an area of more than 5,500 square kilometers. Of the seven species of seagrass in Florida, three are prominent in the Keys: turtle grass (Thalassia testudinum), manatee grass (Syringodium filiforme), and shoal grass (Halodule wrightii). Turtle grass covers the greatest area of sea bottom, forming extensive meadows. It derives its name from its appeal to green sea turtles. Manatee grass, with its round leaves, is usually found in mixed seagrass beds or in small monospecific patches. Shoal grass is a colonizing species that grows in disturbed areas where turtle and manatee grasses have been excluded by environmental conditions. (photo: Heather Dine - Florida Keys NMS)