DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 331 



Ptabmica alpina, L. The numerous plants here brought together do not cliifer more 

 inter se than do the forms of F. vulgaris (with which this is intimately connected), and 

 they are further all united by intermediate forms. P. aljnna itself is found in Arctic 

 Siberia and the Altai; P. oxyloha is only known in Arctic Siberia. P. speciosa, DC. : 

 Ledebour rightly remarks that this is rather a form of vulgaris than a species. P. mul- 

 tijlora, Hk., was originally referred to a var. of vulgaris, from which it differs in its deeply 

 cut leaves, and broad-, short-ligulate flowers. P. Sibirica, Led., is confined to East Siberia 

 and Escholtz Bay. Of the boreaUs, Bong., of Sitcha, I have seen no authentic specimens. 



Chrysanthemum Sibiricum, Turc, is retained by DC, Ledebour, &c., but apparently 

 on very slender grounds. 



C integrifolium, Rich., is an eminently northern form, not found west or north of the 

 Tchuktchi country, and scarcely south of the polar circle ; it may prove to be connected 

 with leucanthemutn by intermediate forms. 



C. leucaiithemum, L., is not Lapponian, but Arctic Russian. C. Segetum is occa- 

 sionally found in Nordland, but apparently rather as an alien than a genuine arctic 

 'plant. 



PYRETHmrM pulchellmn, Turc, is certainly identical with the small arctic form of ino- 

 dormn; and Fries adds as a variety the P. ambiguum, Ledeb., correctly. Ruprecht con- 

 sidered the woolly hairs on the peduncle ot F . pulchellum suflQ.cient to distinguish it ; but 

 this is not the case. 



Artemisia Tilesii, Led. Fries ranks this as a var. of vulgaris, L., both being found in 

 Lapland. Seemann remarks that they occur together throughout Western Eskimo-land. 



A. Chamissoniana, Bess., is reduced to arctica. Less., in 'Flor. Bor.-Am.,' and by most 

 succeeding authors. A. Norvegica, Fr. : in the ' Flor. Bor.-Am.' it is stated that this 

 is identical with A. Chamissoniana ; on comparison I find it has rather larger capitula, 

 but is not otherwise different ; it is a very rare alpine plant in Norway, not entering the 

 arctic circle. 



A. globularia, Cham. I think this is quite tlie sam.e with, glotnerata ; both are con- 

 fined to the country around Behring's Straits. 



A. androsacea. Seem. This is a remarkable and very local plant, which I cannot identify 

 with any more southern species, though, judging from analogy, I suspect that it may 

 eventually prove only an arctic tufted variety of some better-known plant. 



A. ccBspitosa, Bess. I have seen no specimen of this ; but, judging both by plate and 

 description, I do not doubt that Torrey and Gray's surmise is correct as to its being the 

 same with Richardsoniana. 



A. Canadensis, Mich. This, according to Richardson, advances to the arctic circle 

 east of the Rocky Mountains. After a careful re-examination I cannot doubt its identity 

 with A. desertorum, Spr., as also certainly with commutata (3. Gebleriana, Bess, in 

 Herb. Hook. Canadensis is the earliest name. 



BiDENs tripartita, L., is not found in Arctic Lapland, though it enters the arctic circle 

 in Russia. I am quite unable to distinguish the American B. connata, Muhl. 



VOL. XXIII. 2 Y 



