Arctic Plants: Morphology and Synonymy 



41 B 



from the arctic American, the several specimens which I have collected in the 

 Spruce-zone of the Rocky mountains in Colorado agree in all respects with the 

 Siberian plant. 



FiGTJBE L. 

 1. Saxifraga aestivalis Fisch. and Mey ., showing the rhizome, the basal leaves, and the base of the 

 flower-bearing stem (St.); one third of the natural size; specimen from south coast of Coro- 

 nation gulf , Cape Barrow. 2. Same species var. Nelsoniana (Don); a basal leaf ; one third 

 of the natural size; specimen from Herschel island. 3. S. aestivalia; a basal leaf; one third 

 of the natural size; specimen from Siberia; Jenisei, Tolstoi Nos. 



S. Nelsoniana Don. 



This is by Engler referred to the preceding species as a variety; the leaf- 

 blade (Fig. 2) resembles that of the Siberian plant but the petioles are much 

 longer and the flowers relatively larger; the rhizome shows the same structure 

 as described above. 



S. Lyallii Engl, and S. davurica Pall. 



These are both known from Alaska and adjacent islands; they exhibit the 

 same habit as the preceding species but the leaf-shape is quite distinct. 



S. hieraciifolia W. et K. and S. nivalis L. 



These are also members of this section (Boraphila) but their habit is very 

 different from that of S. aestivalis. The rhizome is relatively short but quite 

 stout in the former, and secondary roots develop freely; the almost sessile 

 leaves are arranged in a rosette surrounding the terminal, flower-bearing stem. 

 Axillary buds sometimes develop rosettes contemporarily with the terminal, 

 and several inflorescences may appear upon the same individual. Characteristic 

 of these species of Boraphila is the ea rly withering of the primary root. 



Although quite frequent in the arctic region, S. stellaris L. var. comosa 

 Poir. was not found by the expedition. I mention it in connection with the 

 other species since it is quite an interesting plant showing some structures 

 which recur in members of the section Nephrophyllum. The typical S. 

 stellaris L. has an ascending or almost horizontal rhizome which, according to 

 the substrate, may attain quite a considerable length; for instance, in specimens 

 growing in wet moss the rhizome measures the length of about 18 cm. (specimens 

 from Austria) and bears small, scale-like leaves subtending stolons of the same 

 structure as the main rhizome. In these specimens the aerial leaves are so 

 remote that no rosette is formed; however, in the northern plant a rosette i 



