616 METASPERMAE OF THE MINNESOTA VALLEY. 
I. EXAMINATION OF FAMILIES REPRESENTED IN THE 
MINNESOTA VALLEY. 
The total number of families represented by the metasper- 
mic plart-population of the Minnesota valley is 106. Accord- 
ing t> Engler and Prantl, the total number of metaspermic 
families in the world is 222. Thus 48.0 per cent. of all the 
families in the world are represented within the region of 
our study. Of the 106 families, 21 are Monocotyledones, 60 
are Archichlamydese, and 25 are Metachlamydez. The total 
number of monocotyledonous families is 43,of Archichlamydee, 
131, and of Metachlamydesx, 48. Thus there are in the Min- 
nesota valley, 48.8 per cent. of all monocotyledonous families, 
45.7 per cent. of all archichlamydeous and 52.0 per cent. of all 
metachlamydeous families. Of all families in the valley, 19.8 
per cent. are Monocotyledones, 56.6 percent. are Archichla- 
mydez and 23.5 per cent. are Metachlamydez. These facts 
are condensed into the following table: 
1. Statistics of Families. 
No. in|} Percent. of | Valley per cent. 
valley. | all in valley. of each. 
Monocotyledones............. 21 19.8 48.8 
Archichlamydeae ............ 60 56.6 45.7 
Metachlamydeae............. 25 23.5 52.0 
Total in vailey........... 106 100.0 48.0 
Not all of these families are equally distributed over the 
world. Some are much more limited in their range than 
others. An examination of the general range of the 106 
families represented in the valley of the Minnesota shows that 
they may be divided, according to their range into, six groups 
as follows: : 
Cosmopolitan families. 
Extratropical families. 
Tropical and subtropical families. 
Northern extratropical families. 
Western Hemisphere families. 
North American families. 
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