DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 319 
which are longer than their pedicel, not twice as short. Fries retains arctica, Bchlecbt., 
as a species not yet sufficiently established. 
C. Wahlenbergii, Rupr. (Anglica, Walil., Fl. Lap., non L.). Ruprt^cht remarks of Ihe 
Samoied plant that the leaves are almost those of C. Danica, L., but the siliqiue 
elliptic, the valves sometimes nerved, and much narrower than in true Anglica. 
Hesperis Pallasii, Torr. & Gray. Durand (Kane's Voy.) includes II. minima, T. A: (.i , 
as well as pygmaa, Ilk. In Greenland it has been found only in the extreme north, by 
Kane's Expedition, on Washington Land, lat. 81° N. 
Sisymbrium sophioides, Fisch. This is nothing but an abnormal form of & Sophia, L., 
with a remarkably corymbose inflorescence. It has hitherto been found only in high 
them regions. 
S. brachycarpum, Rich. This, which passes by insensible transitions into S. cancscens, 
Nutt, which inhabits the same regions to the south, often approaches finely-cut-lea v< < I 
states of S. Sophia. 
S. salsugineum, Pall. I have carefully compared with this the Turrit is diffusa, Hook., 
and have no doubt of their absolute identity. 
Erysimum hieraciifolium, L. Ruprecht (Fl. Sam.) refers this to E. strictum, Fl. Wett, 
and notices E. cheiranthoides, L., as occurring very close upon the arctic circle, almost 
at the termination of the woody region. I am quite unable to discriminate between 
these northern Erysima and their southern congeners, nor do I find any satisfactory 
characters for them in books. Fries does not consider either the true hieraciifolium, L., 
or cheiranthoides to be Lapponian ; but E. alpinum, Sm., is so, and is ranked by him 
as an insufficiently established species. Nylander (< Flora Helsingfors,' 31) mentions E. 
alpinum as a form of cheiranthoides, and keeps hieraciifolium distinct. Some idea of 
the difficulty (impossibility ?) of distinguishing these species may be obtained by reading 
Fries's notes (< Summa,' p. 148) and observing the synonyms quoted by Koch under E. 
strictum. 
Braya alpina, Sternb. I think there can be no doubt that B. glabella, Rich., and 
Mia, Br., are both synonyms of B. alpina, Sternb., or, at the furthest, arctic forms of 
that plant. I am quite unable to distinguish them by any good characters. The pods 
are singularly variable in length and breadth, and, as with other arctic Cruciferw, are 
apt to be arrested by cold in early states of development, and hence to assume at later 
periods various forms, depending on subsequent accessions of heat and moisture. 
Braya rosea, Bunge. I have retained this species, though I extremely doubt its distinct- 
ness from B. alpina. The Arctic European habitat is introduced on the faith of Nyman s 
SylLoge,' who quotes Bunge (Cat. Sem. Dorp., anni 1839) for its being a native of Arctic 
Russia (Samojed.) ; but I do not find any of the genus in Ruprecht s Flor. Samojed. 
Cisural. (18-15). . , , ' 
Braya pilosa, Hook. I have repeatedly examined this form very carefully, and, though 
undoubtedly very near B. alpina in general appearance, I am unable to identii> it witft 
any state of that plant. 
< C! 
