GREENLAND FLOWERS 65 
regions in more southern latitudes. It is an inter- 
esting fact that Phy/odoce does not occur on the 
Swiss Alps. 
Cassiope tetragona is a dwarf Arctic shrub of an 
exceptionally wide high Arctic range; it occurs 
on the north-west coast of Greenland and extends 
a considerable distance along the west coast, but 
does not reach Cape Farewell; it is also met with 
along a strip of the northern part of the east coast. 
This species is widely distributed in Spitsbergen; 
itis unknown in Iceland, but grows on the northern 
Scandinavian mountains, and extends along the 
whole of northern Siberia, crossing the Behring 
Strait to Alaska, continuing thence along the 
northern boundary of the American Archipelago, 
spreading to the south-east along the more northern 
ranges of the Rocky Mountains to Hudson Bay, 
and for a considerable distance along the east 
coast of the North American continent and Baffin 
Bay to the eastern regions of the United States. 
Professor Riklit, who has published a very useful 
map of the geographical distribution of this and 
other species of Cassiope, believes that Cassiope 
tetragona began its wanderings in east central Asia. 
1 The following papers by Dr Rikli of Ziirich contain much 
useful information on the distribution of Arctic flowering plants: 
Uber Cassiope tetragona (L.) D. Don., Engler’s Botanische 
Fahrbicher, Bd. (Supplement), p. 268, 1914; Die den 80° N. 
erreichenden oder tberschreitenden Gefasspflanzen, Vierte/- 
jahrsschrift der naturforschenden Gesellschaft in Zirich, uxu, 169, 
1917; Die Arktisch-subarktischen Arten der Gattung PAy//odoce, 
Vierteljahrsschrift (Zirich), xvi, 324, 1921. Other references 
to literature are given in Mr Holttum’s paper quoted in the 
footnote on page 30. 
8. 8.G. 5 
