232 MR. S. MOORE ON THE FLORA 
3. The ‘Fragmenta Phytographie Australie, the Second 
Systematic Census of Australian Plants, and various 
other contributions of the same author. 
4. The Report of the Elder Expedition: Botany, by Baron 
von Mueller and Professor Tate. 
5. Mr. Luehmann's * Reliquie Muelleriane.’ 
6. My own collection. 
Of the 867 species comprising the flora, 7 only are vascular 
Cryptogams, the rest being Phanerogams. The Phanerogams 
include 1 Gymnosperm, 91 Monocotylelones, and 768 Dicoty- 
ledones, the proportion of the latter to the former being as 84 
to 1. That is to say, while 89:3 per cent. of the flora is dieotyle- 
donous, only 10:59 per cent. is monocotyledonous *. These 860 
Phanerogams, disposed among 73 orders, are distributed among 
319 genera, giving an average of only 2'7 species per genus T; and 
while 180 of the genera (56:42 per cent.) are also extra-Australian, 
139 (43:57 per cent.) are confined to the island-continent. No 
less than 146 of the species, or 17 per cent., are endemie in the 
West Australian desert. 
There are no natural orders peculiar to the desert, neither is 
there much reciprocal ordinal exclusion in the parts of it respec- 
tively north and south of 30°. I find records of 8 natural orders 
confined to the desert north of 307, and of as many which, at the 
present time, are not known to overstep that parallel in a north- 
ward sense. The exclusively northern orders are as follows :— 
1. Cupparidee. Represented by Polanisia viscosa, Linn., a 
common weed in tropical and warmer extratropical Aus- 
tralia, but not reported from the S.W. corner 7. 
2. Cucurbitacee. This order has two representatives, which 
advance no further than the Ashburton district. 
3. Araliacee. As the last, but with one representative only. 
4. Jasminee. Comes as far south as the Murchison. 
5. Bignoniacee. One species (Tecoma australis, R. Br.) widely 
* This is a very low proportion. Cfr. Hemsley (Biol. Centr.-Amer. vol. i. 
p. xix), who finds that Europe and four other areas have from 17:32 to 23:43 
per cent. of Monocotyledones, while Australia has 18:5 per cent. 
+ Hemsley (/. c. p. xxiii) gives the following numbers of species per genus :— 
in India 6:0; in Mexico 6:4; in N. America 62; in Australia 6'4. The low 
proportion of species per genus in the West Australian desert is in accordance 
with the rule which prevails in the case of all small floras. 
1 The term “ S.W. corner” is used to denote the tract of land lying south of 
300, and west of the desert as already defined. 
