46 



THE AMERICAN BOTANIST 



The general appearance of the Hawaiian bogs is similar to 

 that of the bogs familiar to continental botanists. The soggy 

 soil is covered with a thick A'egetable mold of decaying turf 

 and mosses, the soil proper being composed of disintegrated 

 basaltic lava, varying in color from dark brown to pale gray. 

 It is exceedingly fine-grained, like ''adobe", and is very ten- 

 acious of its large water content. Under the stunted clumps 

 of bushes and dwarf-trees, there is a considerable accumulation 

 of dead branches and twigs in the mold ; frequently this mate- 

 rial is in an excellent state of preservation. 



The surface of the bogs is covered with tusock-forming 

 grasses, sedges, sphagamus, and other mosses. Abundant 

 species are Panicnin isaclinoidcs, P. imhricatiun, P. iiionticola, 

 Orcohohis fiircatiis, Carcx sandzciceiisis, Deschampia austral is, 

 Lu-.zula hawaiicnsis, and others. There is practically no stand- 

 ing water or pools, although the vegetation is water-soaked, 

 and the rainfall excessive. The bogs are neither treeless, nor 

 is there a continuous arborescent cover. Here and there are 

 clumps of gnarled dwarf-trees, and these clumps occasionally 

 coalesce into larger units. 



Som2 of the distinctive smaller plants, in addition to the 

 turf-plants already enumerated, are : the insectivorous Droscra 

 .longifolia; the elfin Mctrosidcros puinila; a number of endemic 

 woody violets, Viola; a terrestrial orchid. Hahcnavia lioloclula; 

 several Lycopodiiiins ; several AstcJias; several varieties of 

 Planfago pachypJiylla : JJUkcsia Grayana; Gcraniuiii Iiiiiiiile; 

 Lagcjiopiiora inaiiiciisis: Acacjia cxigua; and several woody 

 Lobelias. The dwarf trees comprise a variety of genera and 

 species ; almost all of them are endemic, and the majority are 

 Jiighly precinctive. The Vacciiiiiiiiis are not abundant in the 

 bogs ; in Hawaii their zone of optimum growth is at a lower 

 level than the bogs, and under conditions of lesser humidity. 

 There are none of the pitcher plants, ericaceous forms, Calopo- 

 gojis, or pogoJiias of the continental bogs in the Hawaiian bogs. 



