1903] FLORA OF SOUTHERN CALIFORNIA 273 
Of the families forty-eight are represented by a single genus 
each, and thirty-eight of these each by a single species. The 
families which have the most numerous species are shown below, 
arranged in the sequence of the species: 
GENERA AND SPECIES OF THE LARGER FAMILIES, 
GENERA SPECIES | GENERA SPECIES 
FAMILIES FAMILIES 
: ro-| Na- | In Na- Intro- Native Intro- 
tive | duced] tive |duced tive | duced duced 
Compositae.......} 99 | 1 31204: | 25 ee Beihai 18 3 44 4 
Leguminosae ae eee 2 | 149 5 | Rosaceae ....... ya eae 42 
Gramineae...... 371 © | -o5.|' ge Chenopodiaceae -| 10 ig 36 3 
Polygonaceae ....| 10 | .. | 85 4 OOS: <caiactyet' cm ee Ser igs 
Scrophulariaceae 14 I} 84 I Ranuneulacen rae eee > Ar 28 
ypéraceae:..... 8 60 Cactaceae, .. 2.5. 4 28 
Cruciferae....... 18 i) 2S Euphorbiaceae 4 I 24 2 
olemoniaceae...| 3] .. | 55 | .. | Solanaceae ..... Gah) Ss 22 5 
Umbelliferae..... 21 45 8 Saxifragaceae ee ee 25 
a dle A svilets Pid ee) S94 Wieeet, | PROACORE oer hE A 21 
dro és a : 
iii outa ? oa DE OTAL gta sre Ser) ar 127 1 Ge 
From the above table, it appears that these twenty-one fami- 
lies, being but 17 per cent. of the total number of families, 
include 71 per cent. of all the species which belong in the flora, 
and that the first ten families include 52 per cent. of the species. 
Over 16 per cent. of the entire number of species are found in 
the Compositae, 8 per cent. in the Leguminosae, 6 per cent. in 
the Gramineae,and 4 per cent. each in Polygonaceae and Scrophu- 
lariaceae. 
Some of these families, as the Compositae, the Gramineae, 
and the Cruciferae, owe their prominence to a large number of 
genera of a few species each; but in others this is due to two or 
three genera, or even a single genus which has many species. 
Thus the large development of the genus Phacelia gives impor- 
tance to Hydrophyllaceae, of Gilia to Polemoniaceae, and of 
Carex to Cyperaceae; while the rank of the Leguminosae 
results from the numerous species of Hosackia, Trifolium, 
Lupinus, and Astragalus, and that of the Polygonaceae from the 
many species of Eriogonum and Chorizanthe. In the following 
table the genera which have fifteen or more species are arranged 
in the order of their number: 
