* 
272 BOTANICAL GAZETTE [OCTOBER 
nish, or a powder, from the direct contact of the parching air of 
their arid habitat. 
The same modifications are present also in the plants growing 
in the other areas, but they are not so marked and so prevalent 
as inthe desert vegetation. The ferns may be taken as an exam- 
ple. Only one desert fern (Votholaena tenera) is unprotected by 
a coating of some kind, and although this has small and rigid 
leaves, its excessive rarity may be taken as an indication of its ill 
adaptation to its environment. None of the mountain ferns 
have protective coatings upon their fronds. Eleven of the 
twenty species belonging to the Cismontane area are destitute of 
such protective devices, and nine are furnished with them; the 
former being the species which grow in cool damp situations, 
and the latter those affecting habitats where the supply of moist- 
ure is less abundant or permanent. 
STATISTICS OF CLASSIFICATION. 
The following table presents a summary of the distribution of 
the flora into the several taxonomial categories. The fourth 
column under the head species shows the percentage of the 
species in each class to the total number of species. Only nat- 
uralized or adventive plants are included as introduced, no notice 
being taken of escapes or waifs. These exotics constitute but 
7 per cent. of the species of the flora, a proportion smaller 
than is commonly found. 
SYNOPTIC TABLE OF CLASSIFICATION. 
FAMILIES GENERA SPECIES EI 
TAXONOMIAL = 
CATEGORIES, N % 
a- |Intro-| Na- | Intro- . Intro- Per < 
tive |duced | tive | duced Total | Native duced Total cent.| > 
Gamopetalats .6i..0025 5% 32 r | 216 I 6. 38 55 
Opetalae.........--+-..0. io: | 2 714 51 705 
Chitipetalae sieve dyisasciee 63 rt | 259 27 2 813 5° 863 43 45 
Dicotyledones coco i eben 95 2 | 475 46 | 52z | 1,527 | ror | 1,028 | 82 | 103 
Monocotyledones ............ 17 = 85 14 909 "253 38 291 14 = 
Angiospermae................| 112 2 | 560 60 | 620 1,780 | 139 1,919 97 125 
Gymnospermae .............- 2 ; 7 ie 7 ee ae ee 2r I : 
Spermatophyta......... .....] 1x4 | 2 | 567 | 60 | 627 | x,80r | 139 | 7,040 | 98 | 126 
Peer MOB iy ke oe 6h ibs 7 sf 20 sy 20 41 aes qi 2 4 
TOPAES aS Seats 721 2 | 587 60 | b¢7 | 7,842 | 139 | 7,987 iad 
eee bt 
