590 METASPERMAE OF THE MINNESOTA VALLEY 



Hudson Bay to the Rocky mountains and characterised by Pinus 

 ana, Abies balsamea, Picea nigra, Larix pendula, Picea alba; III, Canadian 

 2one,not clearly delimited, lying southward of the other two and between 

 them, including Manitoba, western Ontario, northern Minnesota, Wis- 

 consin and Michigan, characterised by Pinus strobus, Pinus resinosa and 

 Abies canadensis.) 



(2) Pacific North American Region. (Reaching from the sea to the 

 foot of the Rocky mountains, and south to the Mexican highlands.) 



(a) Californian coast province.between the Coast Range and the 

 sea. Characteristic conifers, Sequoia sempervirens, Pinus insignis, Pinus 

 muricata, Pinus tuberculata, Pinus coulteri, Picea bracteata, Torreya califor- 

 nica, Cupressus macnabiana, Cupressus macrocarpa. 



(b) Oregon province. (Including area west of Cascade moun- 

 tains. Four zones are recognised; I, Kaloschen zone, to 52 north latitude, 

 characterised by Thujopsis borealis; II, Douglas zone, to 43 north latitude, 

 characterised by Abies douglasii; III, Umpqua zone, between 42 and 43 

 north latitude, characterised by Cupressus fragrans', IV, Sierra zone, 

 characterised by Pinus lambertiana and Sequoia gigantea. 



(c) Rocky-mountain province. (Characterised by Pinus flexilis, 

 Pinus monophylla, Larix occidentalis, etc. ) 



(d) Colorado province. (Reaching from Cascade to Rocky 

 mountains, open country.) 



(3) Atlantic North American region. 



(a) Appalachian province. (The forest district of the Atlan- 

 tic North American region, south of the lake province includes three 

 zones. I, Allegheny zone, characterised by Pinus inops, Pinus pungens, Pinus 

 rigida, Picea fraseri, Juniperus virginiana; II, Carolina zone, including New 

 Jersey, Delaware, Maryland, Pennsylvania, Virginia, Georgia; III, Mis- 

 sissippi zone, including the forest district of the Mississippi valley.) 



(b) Prairie province. (The western central and central prairies 

 of the Atlantic drainage, including also the Saskatchewan and Assini- 

 boian prairies of Arctic ocean drainage.) 



Drude: The most recent and most generalised division of 

 the earth into botanical regions is that of Drude. By this wri- 

 ter three main regions are recognised. These are: 



A. Northern realm. 



B. Tropical realm. 



C. Southern realm. 



These three principal regions are subdivided as follows: 



A. Northern realm. 



(1) Arctic region. 



(2) Northern region. 



(3) Middle North American region. 



(4) Mediterranean-Oriental region. 



(5) Lower Asian region. 



(6) East Asian region. 



B. Tropical realm. 



(1) Tropical American region. 



(2) Tropical African region. 



(3) Indian region. 



(4) Malayan-New Zealand region, 



