ECOLOGY OF THE WALLULA GORGE. 289 



Scouleria aquatica in abundance but not fruiting-. This moss 

 is always found on the " up-river " side of rocks where currents 

 strike strongest. On the upper surface an aquatic Hchen, Endo- 

 carpon ininiatuni, was found in quantity ; also a few strands of 

 Scleropodimiv ohtiisifoliiim, a moss usually associated with the 

 Scoulerias. 



The shore line seems to be the habitat of most of the immi- 

 grants transported hither by this all-water route. Mullein was 

 found, also purslain, Portulaca oleracca; cockle bur, Xaiithium 

 spinosum; Russian thistle, Shepherd's purse, and one or two 

 mustards of very hardy habit in bloom on December 10 and 

 again February 15. Well down the banks, below the flood line, 

 was Marsilia vcsfi.va with tomentose rhizocarps, fruiting freely 

 among the shifting sands. Where some bold wall reached down 

 to the moist sands a few plants of Scouring Rush, Equisetunt 

 hyemale, are likely to be found. 



Among the woody plants of this narrow margin is the Desert 

 Juniper, Jiiniperiis scopulorum, having migrated apparently 

 down the gorge of Juniper Canon from the flanks of the Blue 

 Mountains. Of the willows, a cluster of three Salix amygda- 

 loides and a patch of vS". cxigua were found along the exposed 

 bars. The chief tree or shrub is Crataegus columhianuin of 

 Howell, rooted in the shifting sands, crowded with peculiar 

 " galls " and often encrusted with a lichen, Theloschistes lycJi- 

 neus. A few shrubs of wild cherry, Cerasus emarginata, are 

 always associated with Rosa nntkana, and the Golden Currant, 

 Ribiis aurcuui, said to be the same as the cultivated currant of 

 Missouri. 



Among umbelliferous plants, Oregenia fusiforniis is the earliest 

 to flower, its white blossoms contrasting later with the yellow 

 ones of Puccdannm grayi, both in abundance along the flood 

 line, with an occasional Alliiiiii douglassii (sp. ?). Nicotina 

 attenuata, or a similar tobacco, found here, is said to have been 

 cultivated by the Indians. 



Artemisia Iiidoi'ieiaiia, with its densely white leaves, and 

 another sage brush, Artemisia draennculoides, some fifteen feet 

 tall, grow on the talus. The latter is the host of its parasite, 

 Orohrancke Indoviciana. 



