Arctic Plants: Morphology and Synonymy 55 b 



and another specimen of the same species from the Mackenzie river del;fca is 

 figured in the 'accompanying text-figure (Fig. 0) beside a specimen from Switzer- 

 land (Fig. 0: 1). With the only exception that the flowers in the American 

 plant are tetramerous, but pentamerous in the European, the structure of the 

 flower and foliage agrees very well with that of the European; and although P. 

 rotata varies somewhat with respect to the structure of the flower: tetramerous 

 or pentamerous, the calyx-lobes being shorter or longer than the corolla, and the 

 leaves varying in length and width, no transitional forms have been observed 

 so as to make the identification uncertain. P. rotata Griseb. is generally a taller 

 plant with the leaves relatively much longer and narrower than those of the 

 other species, and the narrow calyx-lobes constitute also a good character. 



As stated above, the flower varies from tetra-to pentamerous, the former 

 observed in the specimens from Bathurst inlet; in Greenland both types of 

 flowers occur, and in a large series of specimens from Amur most of the flowers 

 were pentamerous; pentamerous flowers are also characteristic of the plant 

 from Colorado. With regard to the plant from the Hudson bay region, some 

 small individuals from Fort George have only tetramerous flowers while others 

 of normal size have all the flowers .pentamerous; in very tall specimens from 

 Alberta the flowers are constantly pentamerous. The calyx-lobes vary con- 

 siderably in length as may be seen from the figures (Fig. 0: 6, 8, 9, 11, 12 and 13); 

 for instance in some specimens, collected growing together (Figs. 12-13), the 

 lobes may be longer than the corolla, or considerably shorter than this. But in 

 these deviating forms no approach to the floral structure of P. carinthiaca can 

 be detected. 



These two species are strictly annual and of low stature; the tallest speci- 

 mens of P. rotata measures 10 cm. in height, while P. carinthiaca does not reach 

 more than from 2 to 3 cm. 



POLEMONIAGEAE. 



Phlox Richardsonii Hook. 



Densely caespitose, forming large cushions of a diameter up to 18 cm. 

 The primary root persists; it is deep, woody, and branches very little; the flower- 

 bearing shoots are quite long and woody, bearing numerous crowded rosettes 

 of smaU leaves at the apex, surrounding the single, almost sessile, relatively 

 large flowers. The plant thus represents an undershrub. 



Polemonium caeruleum L. var. villosum (Rud.) Brand.' 



Measured from the crown of the very long and slender persisting primary 

 root, the prostrate stem above ground reaches a length of up to 25 cm., and 

 stems of that length are in their fourth year of age. The plant is stoloniferous, 

 and the development of the shoot may be studied from smaller, younger speci- 

 mens. During the first season a rosette of leaves develops; in the second year a 

 terminal inflorescence appears, borne upon a long (about 10 cm.), erect peduncle, 

 naked, or bearing a single leaf supporting a secondary few-flowered inflorescence. 

 From the axil of one of the rosette-leaves a long stolon develops bearing numerous 

 scale-like leaves and terminating in a rosette of green leaves from which the 

 ramification continues as described. The vegetative reproduction is secured, 

 moreover, by long, slender stolons proceeding from the axils of the scale-like 

 leaves; thus the plant is able to spread over an area of quite considerable size. 



' Polemoniaceae, in A. Englei , Das Pflanzenreich. Berlin, 1907. 



