STANDLEY FLOEA OF GLACIER PAEK. 243 



water plays a more or less important part in plant dissemination in 

 mountain regions, for the streams often bring down seeds from 

 alpine slopes even to the plains, and the plants thus propagated 

 frequently thrive at low altitudes. Epiloiium latifoliiim is certainly 

 a typical plant of alpine meadows and rock slides, but it is found in 

 Jiiany places along streams at low altitudes, often in considerable 

 abundance and in greater luxm-iance than at high altitudes. Along 

 the creek at St. Mary Dry as drummondii is more abundant and Jnore 

 vigorous than above timber line, yet it is evident to any botanist 

 that the plant is there only by accident. Along the creek at the 

 east entrance stra}^ plants of many alpine species may be foimd. 



Tliere is a conspicuous difference between the forests of the- east 

 and west slopes of the park. As indicated above, there are several 

 important timber trees which grow only on the west slope, although 

 there are none peculiar to the east slope. Moreover, on the west 

 slope the timber is much denser and the trees are larger (see pi. 38, B). 

 The general appearance of the forest is very different on the two 

 slopes, the differences becoming conspicuous just as soon as one 

 crosses the continental divide. The greater development on the 

 west slope is due presumably to the greater amount of rainfall in 

 that region, and probably also to the lower elevation. 



It is rather remarkable that while the differences between the 

 forests of the two slopes are so strongly marked, there are no pro- 

 portionate differences in the case of the herbaceous and shrubby 

 vegetation. The predominating species of the herbs and shrubs 

 are largely the same, and the differences in the general appearance of 

 the vegetation are mostly such as are to be expected as a consequence 

 of the differences in forest density. On the west slope the forest is 

 in many places so dense that there is scarcely any herbaceous vegeta- 

 tion, but on the east slope there is always a luxuriant growth of 

 herbaceous plants. 



The following shrubs and herbaceous plants are chiefly or entirely 

 confined to the west slope: Taxus hrevifolia, Scheuchzeria palustris, 

 Lysichiton T<:amchatcensis, Tiillium ovatum, NympJiaea polysepala, 

 Drosera rotundifolia and D. longifolia, Opulaster malvaceus, Potentilla 

 palustris, Ruhus leucodermis, Rosa gymnocarpa, Aralia nudicaulis, 

 Echinopanax horridum, Cicuta hulhifera, Ledum glandulosurn, Vac- 

 cinium canadense, Melampyrum lineare, and Viburnum paucijiormn. 

 Most of these are species which are typical of the Pacific slope, but 

 their total does not form an important percentage of the whole 

 herbaceous vegetation. In the case of the trees of the Canadian 

 Zone over 40 per cent of the species are found only on the west 

 slope, and it might be expected that an equal proportion of the 

 herbaceous species would be similarly restricted. On the east slope 

 of the park the writer collected many species of herbaceous plants 

 2048— 'i'O 2 



