Along the initial section are the native shrubs `ulei and pukiawe. Sprawling `ulei has small, oblong leaves arranged in pairs; clusters of white, roselike flowers; and white fruit. Early Hawaiians ate the berries and used the tough wood for making digging sticks, fish spears, and `ukeke (the musical bow). Pukiawe has tiny, rigid leaves and small white, pink, or red berries.
Before entering the guava tree tunnel, look for the native shrub `akoko. It has rounded, oblong leaves arranged in pairs. The branches are dark brown and jointed with white rings. Early Hawaiians used the milky sap mixed with charcoal to stain their outrigger canoe hulls.
In the stands of guava watch for the `elepaio, a small native bird. It is brown on top and white underneath with a black throat and a dark tail, usually cocked. The bird roams the forest understory catching insects on the fly or on vegetation. `Elepaio are very curious, which is why you can sometimes see them.
On the flat section after the two switchbacks, look for hala pepe, a tall, slender native tree. The narrow leaves hang in bunches from the branch tips. The tree produces clusters of yellowish blossoms and then red berries. Early Hawaiians used the flowers in making lei (garlands).
On the final climb watch for kopiko, a native member of the coffee family. It has leathery, oblong leaves with a light green midrib. Turn the leaf over to see a row of tiny holes (piko [navel]) on either side of the midrib. The kopiko produces clusters of little white flowers and fleshy, orange fruits.
Just below the summit listen for the Japanese bush warbler (uguisu), a bird often heard, but rarely seen. Its distinctive cry starts with a long whistle and then winds down in a series of notes. The bush warbler is olive brown on top with a white breast and a long tail.
After taking in the expansive view at the top, look for the native shrub pu`ahanui (kanawao), a relative of hydrangea. It has large, serrated, deeply creased leaves and clusters of delicate pink flowers. Early Hawaiians used the plants for medicinal purposes.