Plant Invasion on Lava Flows. 19 



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

 goats occasionally cross the flow. 



Several days 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: 



FILICES. 



Asplenium trichomanes L,., var. Polypodium pellucidum Klf.,var. 

 Doryop ten's decora Brack. The folded form. 



Sadlcria cyatheoidcs Klf. 



PHANEROGAMS. 



Chenopodium sandwicheum Moq. Verbena bonariensis L. 



Argctnonc mexicana L. 1 plant. Solarium nigrum L,. 



Dodonaca viscosa L. Erigeron bonariensis L. 



Metrosideros polymorpha Gaud., Gnaphalium sandwicensium 



var. Gaud. 



Cyathodcs Tameiamciac Cham. Sonchus oleraceus 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 remainiug five 

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

 were Metrosideros polymorpha, Polypodium pellucidum and Sadlcria 

 cyatheoidcs. 



Dr. \V. T. Brigham 4 visited this flow in 1864. He reports 

 having observed ferns in some of the caves, and a Polypodium 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. 5 Both 



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

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



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



