286 BOTANICAL GAZETTE [APRIL 
Hudsonian lakes are generally fringed by Salix glaucops, Ledum 
glandulosum, and Phyllodoce Breweri; while along the marshy 
margins of the outlet will be found Carex straminiformis, Viola 
Macloskeyi, Dodecatheon alpinum nanum, and Kalmia glauca 
microphylla. 
ARCTIC-ALPINE.—A feature of the flora of the boreal region as 
compared to the Transition is the gradual merging of the forest 
and meadow due to the thinning out of the former. At tree line 
the forest becomes zero and the meadow becomes the dominant 
formation, for in a sense the rocky fields about the summits them- 
selves are inchoate meadows; between the boulders meadow 
conditions prevail. These diminutive meadows do not differ essen- 
tially from the larger expanses below the rock fields. The only 
formations to dispute the territory are that of rock crevices and 
the true lithophytes. 
As stated above, it is questionable if a true climatic tree line 
exists about Lake Tahoe; nevertheless certain plants (Oxyria 
digyna, Ranunculus oxynotus, Draba glacialis, Juniperus communis 
sibirica, Primula suffrutescens, Hulsea algida, Ivesia Schockleyt 
may be cited) are present, which are constantly found only above 
tree line in regions where such a line unquestionably exists. In 
the absence of a better understanding of this vestigial arctic- 
alpine flora, a discussion at present would be premature. 
STANFORD UNIVERSITY 
LITERATURE CITED 
1. Rew, J. A., The geomorphogeny of the Sierra Nevada northeast of Lake 
Tahoe. Univ. Cal. Pub. Geol. 6:89-161. rg1t. 
2. LinpGREN, W., Truckee Folio. U.S. Geol. Atlas, folio 39. 1897. ~ 
3. Lawson, A. C., The geomorphogeny of the Upper Kern River. Univ. Cal. 
Pub. Geol. 3:291-576. 1904. 
4. De MartonnE, E., Traité de geographie — Paris. 1909. 
5. Hann, J., Handbook of climatology. Pt. r. General climatology. Ward’s 
transl. New York. 1903. 
6. ScHROETER, C., Das daserae: der Alpen. Eine Schilderung der 
Hochgebirgsflora. Ziirich. 
7. prmte J. N., Snowfall in Be Sierra Nevada. Sierra Club Bull. 6:310- 
354. % 
