8 THE AMERICAN BOTANIST 



cake down into a tough spongy matting - , that is serviceable for 

 several years without repair. Occassionally fences are made by 

 stacking up like cord wood three or four foot lengths of fern 

 trunk. The terminal buds, and numerous lateral buds, sprout 

 vigorously, and soon the spongy wall is clad in a mantle of 

 green fronds. 



The fertile leaves are readily distinguished by the conspicu- 

 ous bivalved indusia. These form a thick beaded rim along 

 each margin of the segments. The indusium is coriaceous, and 

 several millimeters in diameter. Both the inner and outer valve 

 is free from the leaf segment. The spores are produced in 

 enormous quantities, and are pale brown in color. 



The finest fern forests in Hawaii are on the very wet slopes 

 of the Kohala Mountains, but those most accessible to the 

 traveller are in the vicinity of the Crater Kilauea. These occupy 

 an area of many square miles, at 1000-4000 feet elevation. The 

 oJtia Iclma (Mctrosidcros polymorphs) is the dominant hard- 

 wood tree of this district. Its slender gray trunk rises to a 

 height of sixty or eighty feet. Under its fine-leaved, open 

 canopy the tree ferns form a dense and unbroken undercover. 

 Both species occur here, the kapu the more abundant, the 

 hapu i'i'i the more conspicuous by reason of its stature and 

 spread. Cibotiitm glaucum closely resembles the hapu and has the 

 same geographic distribution, but is rare. According to Hille- 

 brand, forms occur which are intermediate between the two 

 species. 



The lehua and the tree ferns give theKilauea region its dis- 

 tinctive aspect, but a number of other trees and shrubs occur 

 scatteringly through the forest. Chief among these are, — 

 Suttonia Lessertiana, Cheirodendron GcmdichawJtii, Ilex Sand- 

 wiccusis, Rubus jamaicensis, Broussaissia arguta, Stenogyne 

 calaminthoides , and several Cyrtandras. The soil is a thick, 

 mi list vegetable mold, overlaying ancient lava flows. In the 

 forested district are many pit craters and steam cracks. 



