20 VEGETATION IN COLORADO-HOLM. [MEM01 Vol. Tix 1 ; 



monantha of all the other regions. For this reason one might suppose that the Rocky Moun- 

 tains represent another geographical center of this species, a stouter plant with the flowers 

 larger; but the fact that Omalocarpus is monotypic on this continent, and moreover confined to 

 Colorado, California, northwestern Canada, and Alaska, seems to indicate that A. narcissi- 

 flora did not develop in these mountains as a species, but that it came from Asia, and evidently 

 from Altai, by way of the northeastern corner, the only place where the distribution reaches the 

 Arctic regions — St. Lawrence Bay. 



Ranunculus adoneus Gray. 



A native of the Rocky Mountains of Colorado, and of the Wasatch, Utah; it has an ally in 

 Washington— R. triternatus Gray; furthermore, R. Suksdorjii Gray from Washington and 

 Oregon, and R. eximius Grne. from Colorado to Idaho are, also, related to this species. Thus 

 all are natives of these mountains, and represent a very characteristic section of the genus. 



The Arctic R. nivalis L. does not extend to Colorado, but is represented by an analogue, 



R. Macauleyi Gray, which is a native of the higher mountains of southern Colorado and New 



Mexico. 



Caltha leptosepala D C. 



In North America the genus Caltha is represented by the circumpolar C. palustris L. ; by 

 G. natans Pall, which inhabits wet sphagnous bogs and flowing water, British America, Atha- 

 basca plains and northward, and is known also from Minnesota, at Tower and in Vermillion 

 Lake; the main distribution of the species is, however, northern Asia and Kamchatka. As this 

 is an aquatic plant the wide, geographical distribution is not surprising. Then there are 

 two other species, C. leptosepala. D C. and C. biflora D C, both of which have been recorded 

 from Alaska south to California. With respect to C. palustris, although being circumpolar, 

 the center of geographical distribution is evidently located south of the Arctic Circle, where 

 the species reaches its highest development, and is accompanied by several more or less charac- 

 teristic forms. But the Rocky Mountains seem to be the center of distribution as well as of 

 development of the species C. leptosepala, and of C. biflora. Characteristic of these two species 

 is the white or bluish-white colors of the sepals, and the stipitate follicles. 



Trollius laxus Salisb. 



This is the only species represented on this continent from New Hampshire to Michigan 

 and south to Delaware. In the Rocky Mountains the variety albiflorus Gray is recorded from 

 British America to Colorado and Utah and to the Cascades in British Columbia. The typical 

 plant, as well as the variety albiflorus, thus have originated on this continent, and they are quite 

 distinct from the European and Asiatic species. 



Papaver nudicaule L. 



''Everywhere upon the shore of the Arctic Sea throughout the whole breadth of the con- 

 tinent, and in the islands," and "upon the Rocky Mountains at a great elevation" is the dis- 

 tribution of this plant in Canada, according to Macoun. 15 Furthermore, the species is known 

 from Alaska and from Grays Peak in Colorado. It is very frequent in Greenland and extends 

 from there throughout Arctic Europe and on the mountains of Norway (Dovre). In Asia it 

 extends from Ural to Kamtschatka, and it is abundant in the Altai and Baikal Mountains. 

 Several varieties are described, and not less than seven are recorded from Altai and Baikal, 

 according to Turczaninow (1. c, p. 96). In North America a near ally P. Macounii Grne. has 

 been found on the Pribilof Islands, and, strange to say, another species P. pyrenaicum L. has 

 been discovered in the Rocky Mountains — Alberta, Sheep Mountain, Waterton Lake, 16 and 



is Catalogue of Canadian Plants, pt. 1, p. 34. Montreal, 1SS3. 



10 The Canadian specimens of this Papaver were submitted to the writer by Mr. James M. Macoun, with the request to describe it as a new 

 species. However I recognized it at once to be identical with the Pyrenean plant, and my determination was promptly verified by the botanists 

 at Kew. In looking through the material of P. nudicauleiu the United States National Museum I found some other specimens from Montana (1. c.) 

 which also belong to this Interesting species. 



