HAWAIIAN TREE FERN AS A SOURCE OF STARCH 



3 



Hillebrand 4 lists another species, G. glaucum, but states that it 

 is rather rare. , 



Cibotium chamissoi, or " Hapu " as it is popularly known, is easily 

 recognized by its yellow pulu or hair and its comparatively short, 

 stocky growth. In many forests it constitutes more than 50 per 

 cent of the entire tree-fern growth. The trunk sometimes attains a 

 height of 16 feet, but usually does not exceed 10 feet. The diameter 

 of the trunk is usually 8 to 12 inches. (PL I, fig. 1.) G. menziesii, 

 or " Hapu Iii," is distinguished by the brownish or blackish pulu which 

 covers the stipes and fills the crown. Occasionally it attains a height 

 of 40 feet and frequently a diameter of 3 feet. (PL I, fig. 2.) 

 Another species, commonly known as the " Meu," is easily recognized 

 in the Hilo district by its very slender trunk, smaller fronds, dull, 

 lusterless, rather scant, yellowish-brown pulu, and nearly naked 

 stipes. (PL I, fig. 3.) The "Amau " (Sadleria cyatheoides) , 

 although a different genus of tree fern, is also of interest since it is 

 exceedingly common in occurrence and has a starchy core. 



OCCURRENCE IN HAWAII 



The tree fern is found in all parts of Hawaii where there is an 

 annual rainfall of 100 inches or more. It grows on nearly all the 

 mountains, but occurs in dense forests only on the islands of Kauai 

 and Hawaii. On Kauai the forests are too inaccessible to be of 

 importance for starch production, but on Hawaii they occur in al- 

 most unbroken stretches from sea level to an elevation of 6,000 feet 

 or more. These long stretches are reached both by rail and auto- 

 mobile roads running from Hilo to the Kilauea Volcano. The wind- 

 ward slopes of the Mauna Kea and Mauna Loa Mountains are one 

 continuous tree-fern forest, the belt extending from the Puna dis- 

 trict to the Hamakua district being about 10 miles wide and 40 miles 

 long. In general it is estimated that there are 400,000 acres of tree- 

 fern forests on the island of Hawaii alone. A very large part of 

 this area is within the forest reserve or on Government-owned lands, 

 from which it is illegal to cut the tree fern. There are, however, 

 many thousands of acres of privately owned land on the island of 

 Hawaii, which in its present state is of little value because the 

 dense growth of tree ferns unfits it for pasture and the heavy cover- 

 ing of leaf mold keeps the soil too wet for general agricultural pur- 

 poses. The owners of these lands regard the tree fern as a pest and 

 would welcome any means of removing it. 



STUDIES OF METHODS OF PROPAGATION AND GROWTH 



It was felt that before the tree-fern starch industry could be 

 established on a large scale in Hawaii some feasible method must 

 be found for providing a permanent source of the raw material. 

 Many of the tree-fern areas are hard to reach, and it is almost im- 

 possible to secure the raw material at any great distance from the 

 established roads because of the rough topography and the heavy 

 leaf mold. Moreover, the cost of getting the raw material from the 

 depths of the forest, when the supply adjacent to the highway became 

 exhausted, would reach a prohibitive figure. 



4 Hillebrand, Wm. Flora of the Hawaiian Islands, p. 547. 



