20 BUREAU OF GEOLOGY
Thousands of years ago, the island began as a living coral reef jutting up from the sea floor. As great quantities of water began to freeze into glaciers at the earth's poles, the sea level dropped, exposing the top of the reef and forming an island composed of fossilized coral rock.
As time passed, storm tides and waves left seaweed, driftwood, and other organic debris stranded on the bare rock. This material began decaying and forming small pockets of soil in depressions in the coral rocks. Then a few seeds arrived from other tropical islands some floating on the sea or carried by the winds, while others came in the digestive tracts of migrating birds. The seeds sprouted and began to grow, drop leaves, produce flowers and seeds, mature, die, and decay. With the passing of each generation. a complex and diverse tropical hammock colonized the remains of this ancient coral reef.
The virgin tropical forest that thrives here is typical of the kind of scenery that was once enjoyed on most of Florida's Upper Keys. As the Keys were developed to accommodate an increasing number of people, most of the unique vegetation was scraped away making the tropical forest of Lignumvitae Key a very rare and special place. Here, a visitor can walk in the shade of trees with strange names like strangler fig, poisonwood, lignumvitae, and gumbolimbo.
Access to the Key is limited to privately owned boats or charter boats available at nearby marinas. A two-hour guided tour of the island and the Matheson House is given at 9 AM and a one-hour tour at 1 PM and 3 PM from Wednesday through Sunday. The visitor should wear walking shoes and bring mosquito repellent. To protect the fragile vegetation and environment of the Key, visitors must stay within the clearing except in the company of the interpretive guide or ranger. For further information, write or phone Ugnumvitae Key State Botanical Site, c/o Long Key State Recreaban Area, P. 0. Box 776, Long Key, FL 33001. Telephone: (305) 664-4815.
INDIAN KEY STATE HISTORICAL SITE
Indian Key is located about three-quarters of a mile to the southeast of the north end of Lower Matecumbe Key (Figures 16, 17 and 18). Even though it is in front of the main reef tract the geological history of Indian Key is similar to Lignumvitae Key, discussed above. A small patch reef, exposed by falling sea level, formed the limestone foundation for Indian Key.