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No. 6
  

HOW PLANTS CAN ADAPT TO UNFRIENDLY LIVING CONDITIONS
Many living things are able to change in order to make themselves more suitable to their environ-ment. This ability to adjust is called adaptation. For example, certain animals hibernate through the cold winter; others grow thick coats of fur to adapt to colder seasons. The cactus, a desert plant, has developed a stem that stores water so that it may continue to live during times of little rainfall.

HAWAII'S PLANTS
Many plants in Hawaii have made adjustments. Some plants have learned to adapt to the unusual and unfriendly living conditions found on the coast in Hawaii. The beach morning glory, the beach naupaka and the ilima are indigenous (native) plants that have adjusted to living along the sea shore. Each in its own ways has adapted to the salt spray, ocean breezes, high surf and intense sunshine found in the beach environment.

THE BEACH MORNING GLORY (POHUEHUE)
The beach morning glory, called pohuehue in Hawaiian, is a smooth green vine that grows in the sand just beyond the reach of the waves. Its thick leaves are two to three inches long. Its pink bell-shaped flower lies close to the ground, which gives it some protection from the wind. It adapts to living in the hot sun and blowing sand by opening its petals only in the cool morning hours. If the beach morning glory is broken up by storm waves, the whole plant need not die.

The vine has slender stems called "runners." Roots grow at the joints or nodes of each of these runners. If pieces of the vine are broken off by the sea or wind, new roots can develop at these nodes and take hold in the sand. This adapta-tion not only helps the morning glory survive in its coastal home, but also gives it the ability to hold sand dunes together, which is very important in stopping erosion of the beaches.

Some Surf History:
Ancient Hawaiians slapped the stems of the pohuehue on the ocean and chanted to make sure they had good waves for surfing!

 

Beach Morning Glory (Pohuehue)
 
THE BEACH NAUPAKA (NAUPAKA-KAHAKAI)
The beach naupaka grows wild along many Hawaiian shores. It is an attractive shrub with shiny green leaves. It usually grows close to the ground, but it can grow to heights of five to ten feet. The naupaka has succulent (fleshy or juicy) leaves and fruit; this moisture protects the plant from the intense heat of the sun. The oval-shaped leaves are from three to five inches long and grow in a tuft or small cluster at the tips of the long branches. These tufts protect the growing tips from harsh sea winds and salt spray. The white berries of the naupa-ka have become

Naupaka Kahakai
 adapted to salt and they can float on the ocean cur-rents. The currents and tides help spread the berries, which contain the seeds of the plant, to other shorelines in the islands. From these seeds, new naupaka plants can grow. Like the beach morning glory, the naupaka has a root system that helps protect it from strong wind and waves. If a branch is broken or damaged, new roots will form near the break to help anchor the plant and keep it growing. This adaptation has made the naupaka a favorite of coastal gardeners, who use it as an ornamental windbreak and for erosion control. Most people identify the naupaka by its 3/4-inch white flower with purple streaks, which looks like it might have been torn in half. Actually, the five-petaled flower is com-plete, but its unusual appearance has made it the subject of several Hawaiian legends.

 

ILIMA
The ilima grows in many parts of Hawaii, from sea level to an altitude of more than 2,000 feet. The plant can grow to be four feet tall, but when it grows along the coast it usually spreads out close to the ground. By keeping a low pro-file the ilima can protect itself from the salty sea wind. Other adapta-tions of the ilima are in the leaves. The heart-shaped leaf of the ilima has hundreds of tiny hairs. These hairs help break up the strength of the wind as it blows across the plant. The hairs

 


Ilima

also keep the salt spray from the surface of the leaf. The leaves' silvery color reflects the hot rays of the sun, helping the plant stay cool and moist. The delicate yellow and gold blossom of the ilima has been named the "flower of Oahu." The flowers can be strung into lovely leis which are prized.
 
CAN THESE PLANTS ADAPT TO MAN?
We have learned how three of Hawaii's coastal plants successfully survive strong sunlight, salt spray, ocean winds, high surf and other unfriendly living conditions Mother Nature sets forth. Unfortunately, they are less successful in adjusting to the special problems caused by man. Foot traffic, dirt bikes and dune buggies can seriously damage these coastal plants by ripping and tearing the leaves, nodes and root systems. Because these plants are important in stopping erosion of the beaches and sand dunes, we should take care to protect them.