Plant Invasion on Lava Flows. 19 



I believe that distribution is mainly by wind, although cattle and 

 goats occasionally cross the flow. 



Several daj's later this flow was again visited at a somewhat 

 higher elevation, at a place not far distant from the Judd road, and 

 about ten miles above Puuwaawaa. There was relatively less 

 vegetation, but distribution was the same as observed in the first 

 case. At this place there are several islands of an ancient aa flow 

 which are covered with vegetation. The following plants were 

 observed in the cracks on the pahoehoe, only the common white 

 lichen being observed on the aa: 



FII.ICES. 



Aspleniiim trichoinancs L,., var. Polypodiiini pcllncidiun Klf.,var. 

 Doryopteris decora Brack. The folded form. 



Sadlcria cyathcoidcs Klf. 



PHANEROGAMS. 



Chenopodium sandzvichejun Moq. Verbena bonariejisis L. 



Argemone niexicaiia L. i plant. Solantun nigi'uni L,. 



Dodonaea viscosa L. Erigeron bo7iariensis ly. 



]\fetroside?'os polyniorpJia Gaud., Gnaphaliiini sandzch'cnsi nm 



var. Gaud. 



Cyathodes Tamciamciae Cham. Sonchus oleracciis L. 



Of the ten phanerogams, five are native and with Sophora 

 chrysophylla , which was not observed on the flow, constitute the 

 prevailing flora of the surrounding region. The remaining five 

 belong to the naturalized flora. The prevailing plants on the flow 

 were Mctrosidcros polymorplia , Polypodiuni pelhicidum and Sadlcria 

 cyathcoidcs. 



Dr. W. T. Brigham^ visited this flow in 1864. He reports 

 having observed ferns in some of the caves, and a Polypodiiini on 

 the surface cracks, but lichens were rare. 



From a station called Honomalino the flows of 1887 and 1907 

 were visited. The flow of 1887 was observed at the place where 

 it branches and flows around a cone called Puu Ohia.^ Both 



*Dr. W. T. Brigham: Volcanoes of Kilauea and Mauna Loa. B. P. B. M. 

 Mem., vol. ii, no. 4, p. 16. 



^This cone is called Puu Ohohia on the Government map. 



