Alpine and Boreal Floras of Western America. 257 
25 per cent to northwest coast-types").. Of the. distinctively Sierra species, 
50 per cent are especially developed local types, and 5o per cent belong to 
types common to the Sierra and the southern Rocky Mountains. These facts 
point not only to the great antiquity and effectiveness of the Klamath Gap, 
but also to a former east and west continuity of boreal species between the 
Rocky Mountains of Utah and Colorado and the Sierra Nevada of California, 
a distance of at least 500 miles. 
The following lists of plants will represent the relationships of the boreal- 
alpine flora of Mount Shasta, the Cascade range and the Sierra Nevada 
Mountains. In giving these lists, a characterization of the different regions is 
also established. 
a) Boreal-alpine species common to Shasta and the Sierra-Cascade System. 
Achillea borealis Bong. (= A. mille- 
folium L.). 
Aconitum columbianum Nutt. (= A. 
Fischeri Reichb.). 
Allium validum Wats. 
Alnus sinuata E. Regel. 
Antennaria media Greene. 
Arabis platysperma Gray. 
Arctostaphylos nevadensis Gray. 
Dicentra (Bicuculla) uniflora Kell. 
Cardamine bellidifolia L. var. pachy- 
Carex Breweri Boot. [phylla Coville. 
Chimaphila Menziesii Spreng. 
» umbellata Nutt. 
Chrysothamnus Bloomeri Gray. 
Cymopterus terebinthinus Torr. &Gray. 
Drosera rotundifolia L. 
Epilobium obcordatum Gray. 
» Pringleanum Hausskn. 
Eriogonum pyrolaefolium Hook. 
Gentiana simplex Gray. 
Habenaria leucostachys Wats. 
» unalaschkensis Wats. 
Holodiscus discolor Maxim. 
Juncus Parryi Engelm. 
Kalmia glauca L. var. microphylla 
Hook. 
1) MERRIAM 1. c. p. 82—86. 
Harshberger, Survey N.-America. 
Mimulus primuloides Benth. 
Mitella pentandra Hook. 
Oreobroma triphylla Wats. (= Clay- 
tonia triphylla Wats.). 
Orthocarpus pilosus Wats. 
Oxyria digyna Campd. 
Pentstemon Newberryi Gray (= P. 
Menziesii Hook.). 
Phlox Douglasi Hook. var. diffusa Gray. 
Polemonium pulchellum Bunge 
(= P. humile Willd.). 
Polygonum shastense Brewer. 
Potentilla flabellifolia Hook. (= P. ge- 
lida C. A. Meyer). 
Pulsatilla occidentalis Wats. 
Pyrola picta Sm. 
Sagina saginoides L. (= 5. Linnaei 
Pursh). 
Saxifraga Tolmiei Torr. & Gray. 
Sibbaldia procumbens L. 
Sorbus sambucifolia Roem. (= Pyrus 
sambucifolia Cham. & Schlecht.). 
Spraguea umbellata Torr. 
Viola blanda Willd. 
»  purpurea Kell. (= V.aurea Kell. 
var. venosa Wats.). 
