Since mushrooms generally require plenty of water, you would not expect to find them at the beach. Several species, however, may be discovered here. The most readily identifiable is the Earth Star (_Geaster hygrometricus_), which resembles a Puff Ball but differs in having the outer layer of the skin divided into tough, star-shaped segments. During the dry seasons, this star is drawn up around the ball by its contraction, thus protecting it against further desiccation. In wet weather, the ball swells and holds the star against the ground to allow for water absorption. The “roots” of the Earth Star are shallow, so the plant may readily be dislodged. The wind easily blows it across the dunes, spreading the spores over a wide area. NOW IT’S UP TO YOU There is something new to be known about every animal and plant. Now it’s up to you! Careful observation will allow you to discover many other examples of special adaptation to life in the shifting dunes, and the next chapters will introduce you to some of the more common of the living things inhabiting this strange sand-world. And if you wish to read more about ecology, try these books: Ernest Neal, _Woodland Ecology_. Cambridge, Mass.: Harvard University Press, 1958. $1.75 John H. Storer, _The Web of Life: A First Book of Ecology_. New York: New American Library, 1956. $.35 Chapter 3 PLANTS ON THE DUNES Plants add embellishment to the earth. For thousands of years people have valued them for their elegance and their usefulness. They may rate no more than a passing glance in fields and woods, but at the beach they stand out boldly, for here they seem almost out of place. We have already become acquainted with some strange beach-dwelling plants; now let us examine more closely a few of the most common species. MUSHROOMS ON THE DUNES [Illustration: Earth Star] Earth Star (_Geaster hygrometricus_) Star-shaped fleshy skin at base Main, central body is round The flower-like shape of this common mushroom always amazes its discoverer. The basal star is actually a protective coat that covers the ball during dry spells. Its scientific name, _Geaster_, means “earth star.” _Hygrometricus_ means “water-measuring,” and refers to the opening and closing of the star. GRASS ON THE DUNES [Illustration: Beach Grass] Beach Grass (_Ammophila breviligulata_) Typical grass shape Sharp, stiff tip to blade Beach Grass is the most common xerophyte here. It forms dense mats everywhere, and once it gains footing, spreads at a remarkable rate. When windy weather bends the blade it sometimes scribes circles in the sand. If these are deeper on one side or incomplete, they help determine the direction of the prevailing wind. Beach Grass can be extremely uncomfortable to bare legs—so beware! FLOWERS OF THE SEASHORE