A few million years ago: A spore from a fern somewhere in southeast Asia is released into the wind and carried by a rising current eight miles high into the jet stream, where it is borne eastward. Eventually it drifts down and settles on a barren lava field in the middle of the Pacific Ocean. This is one of the ways life came to the Hawaiian Islands. Where barren flows once existed, forests now grow. Insects, seeds, and spiders also reached the islands by riding the air currents, but there were other ways. Migrating or storm-driven birds carried seeds either in their digestive tracts or stuck to their feathers. Pacific Ocean currents transported salt-resistant seeds and rafted insects, plants, and snails on floating debris. Amphibians, reptiles, freshwater fish, and most mammals were unable to cross the vast expanse of ocean — only the monk seal and hoary bat succeeded. Of the millions of organisms that embarked on this chance voyage, very few made it here, and of those that did, few survived.

Over a span of about 70 million years, plants and animals colonized Hawai'i at the rate of roughly one every 70,000 years. These species changed gradually with time — they evolved into new forms that were better adapted to island life. In the absence of predators and competitors found in their former homelands, their survival no longer depended on elaborate defense mechanisms. Those qualities that once protected them proved unnecessary and were eventually lost. Contradictory terms describe these new life forms: nettleless nettles, mintless mints, stinkless stink bugs, and flightless birds.

More than 90 percent of Hawaii's native flora and fauna is endemic — found nowhere else on earth. The island's 100 endemic land birds evolved from as few as 20 original ancestors; a thousand kinds of flowering plants evolved from 272 colonizers; over 1,000 mollusks evolved from at least 22 immigrants; and about 10,000 insect and spider species evolved from 350 to 400 precursors. The astounding diversity of life that flourished on these isolated, once barren islands bears witness to the force of evolution and the tenacity of life.

Use the following guide to identify some of Hawaii's fascinating plant life. The Halema'uma'u Trail provides a tour of these botanical specimens. The Trail takes you through a tree-fern forest and into the heart of one of the world's most active volcanoes. Your walk may begin either on the crater side of the Volcano House Hotel, or at Halema'uma'u. A variety of optional, longer routes may be added. You can obtain a map showing Kilauea summit hiking trails at the Visitor Center. Take a hike, and look for the following plants