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BRUCE holst

plenty of recreational opportunities. For more information about Sarasota County preserves, visit the Sarasota County Natural Resources Department website: NaturalResources BRUCE holst

The Eastern purple bladderwort (Utricularia purpurea) is one of the three species of carnivorous bladderworts found at the Preserve.

Bartram’s rosegentian (Sabatia decandra) provides beautiful splashes of color in the depression marshes bruce holst

Florida butterfly orchid (Encyclia tampensis) shoestring fern (Vittaria lineata), golden polypody (Phlebodium aureum), southern needle leaf (Tillandsia setacea), giant air plant (Tillandsia utriculata), resurrection fern (Pleopeltis polypodioides) and abundant Spanish moss (Tillandsia usenoides). The marshes contain a diverse array of wildflower species including milkworts (Polygala spp.), meadow beauty (Rhexia spp.), rosegentian (Sabatia spp.) and St. John’s wort (Hypericum spp.). These marshes contain some of the most interesting and beautiful carnivorous plants including sundews (Drosera capillaris) and three different species of bladderwort (Utricularia spp.). Sundews have tentaclelike glands that secrete a sticky sweet substance that functions to attract and capture insects. These glands also contain enzymes that aid in the digestion of insects providing additional nutrition to the plant. The bladderworts are commonly found in open water areas and capture organisms by means of bladder-like traps. These traps inflate when triggered by the motion of aquatic organisms, which are then sucked into the trap and slowly digested by the plant. In addition to the abundant plant life, Walton Ranch Preserve is home to many native animals including bobcats, deer, turkeys, and Sandhill Cranes. Wild hogs are also present but land managers are working to reduce their numbers through a trapping program. Although Walton Ranch is currently not open to the public, the adjacent T. Mabry Carlton, Jr. Memorial Reserve is open to the public and offers

Epiphytes abound in the mesic and hydric hammocks of the Walton Ranch Preserve, with live oak tree branches covered with ferns, butterfly orchids, and bromeliads.

Roraima-tepui, an Island in Time bruce holst

Bruce K. Holst, Director of Botany

A cloud covered Roraima-tepui can be seen center right. The Tropical Dispatch  January–April 2012


he unique mountains of the Guayana Shield region of northern South America have often been called islands in time, referring to their nearly inaccessible tablemountain summits, some thousands of feet above the surrounding rainforest. The mountains, called tepuis by the local Amerindians, are home to a large number of plant species, including many bromeliads and orchids, found nowhere else in the world. With the prospect of a rapidly warming planet, there is great concern among scientists and conservationists that many of the species that grow on the summits are at extreme risk of extinction. On a typical mountain with continued on next page 5

Tropical Dispatch January 2012