83 
Mountain Plants, which however are found also in the Basin 
Mountains. Among the trees and shrubs which had their 
“origin in Mexico” we find Artemisia tridentata, Purshia tridentata 
and. Cercocarpus ledifolius, all Basin plants and not found in 
Mexico, except the first; and Tetradymia canescens which belongs 
to the Columbia plains. In the list of plants common to Sierra 
Nevada and the Cascade Mountains, on page 254, we find 
Lonicera involucrata, a plant common in the Rockies and extend- 
ing northeast to the Hudson Bay. Оп page 249, it is given as 
transcontinental. Luzula spicata and Potentilla procumbens are 
said to be common to the Sierras and the Rockies ‘‘only.” 
They are both circumpolar arctic-alpine plants. 
A good illustration of carelessness in referring plants to a wrong 
life zone, is given on pages 192-194, where Professor Harshberger 
lists the alpine plants. That a plant occasionally grows at a 
certain high altitude, or that it is found incidentally above what 
seems to be the timber line, does not make it an alpine plant. In 
the list are found the following, which usually grow on treeless 
hills or ridges, but still can not be called alpine: Arabis canescens, 
Vesicaria [Lesquerella] alpina, Homalobus tenuifolius, Balsamor- 
rhiza incana, B. Hookeri, Tanacetum capitataum, Т. Nuttallii, 
Tetradymia inermis, and Pentstemon secundiflorus. The following 
grow on dry plains and foothills: Solidago nana, Stenotus acaulis, 
and Pentstemon humilis. The following wood-plants are in- 
cluded: Mitella pentandra, M. trifida, Lonicera coerulea, Linnaea 
borealis (should have been L. americana), and Arnica fulgens. 
Erigeron Coulteri and Senecio triangularis grow on subalpine 
creek banks, Lithophragma tenella on wet hillsides, Arnica longi- 
folia and Dodecatheon pauciflorum in wet meadows far below the 
alpine zone; so also Primula mistassinica, which is not found in 
the Rockies at all, but belongs to the Hudson Bay region and the 
northeast. These plants, erroneously given as alpine, constitute 
one sixth of the list. 
А. good phytogeographer should differentiate between dif- 
ferent formations due to moisture, to exposure to sun, rain, and 
wind, to altitude, to improper drainage, but these factors are 
almost wholly neglected in the treatment of the Rocky Moun- 
