Distribution of the Flora in 
the Alp 
ine Zone. 
47 
Number 
Number Generic 
of 
of coefficient 
Species. 
Genera, per 
cent. 
Flora of Switzerland 1 ... 
2453 
659 
27 
„ Valais ... 
1850 
592 
31 
„ the region W.T.D. 
661 
221 
33 
,, upper basin of the Trient 
470 
211 
45 
,, 10 areas of alpine grassland ... 
370 
210 
57 
„ 12 areas of Jura grassland ... 
240 
141 
60 
,, 9 localities in Ormonts grassland 92 
73 
79 
,, 1 area of Jura grassland 
106 
90 
85 
It has been demonstrated elsewhere 2 from a considerable 
number of examples that, generally, the generic coefficient varies 
inversely ivith the variety of ecological conditions in the areas compared. 
This is shown very clearly in the table given below, in which a 
a series is given in order of decreasing ecological diversity. 
The factors which have the most influence on the value of 
the generic coefficient are, as has been shown in one of the 
memoirs already mentioned, especially the extent, the topographical 
and petrographical complexity, the degree of isolation, and finally 
the latitude and altitude. In this place only the figures relating to 
altitude will be cited, since this factor is particularly seen in the 
composition of the alpine flora. The following figures, taken from 
data collected by Oswald Heer in his Die nivalc Flora der Schweiz, 
are most convincing in this respect. They show that in the eight 
belts of 500' each established by Heer in the niveal zone of the 
Swiss Alps, above an altitude of 8000' (2600 metres), 3 the generic 
coefficient constantly increases as we pass to higher levels. 
Belts 
(increasing 
altitude). 
I. 
Number 
of 
Species. 
338 
Number 
of 
Genera. 
139 
Generic 
coefficient 
per 
100 Species. 
41-4 
II. 
227 
... 
111 
• . . 
49 
III. 
153 
• . • 
78 
. . . 
51 
IV. 
122 
. . • 
68 
. . . 
55-7 
V. 
47 
. . • 
29 
. • . 
62 
VI. 
22 
. . . 
16 
. . . 
73 
VII. ( 
VIII. \ 
22 
... 
17 
... 
77-3 
1 The n»c\v Flora of Switzerland by Schinz and Keller indicates 
2459 species and 660 genera: the generic coefficient is 
scarcely altered. 
5 Particularly in two of the memoirs whose titles are cited at the 
end of the article. 
3 8530 English feet. 
