Natural Orders .] 
APPENDIX. 
551 
given. Of tlie whole class about 2000 species are at present published, 
and in Terra Australis, where this is the most numerous family, consider- 
ably more than 400 species have already been observed. 
One of the three orders of Leguminosee which is here for the first time 
proposed may be named Mimose/e. It consists of the Linnean Mimosa, 
recently subdivided by Willdenovv into five genera, along with Adenanthera 
and Prosopis. 
This order is sufficiently distinguished from both the others by the 
hypogyrious insertion and valvular aestivation of its corolla, which being 
perfectly regular differs in this respect also from the greater part of Lomen- 
taceae and from all the Papilionaceae. 
Nearly the whole of the Australian species of the Linnean genus 
Mimosa belong to Acacia of Willdenow, as it is at present constituted; 
and about nine-tenlhs of the Acaciae to his first division of that genus, de- 
scribed by him as having simple leaves, but which is in reality aphyllous ; 
the dilated foliaceous footstalk performing the functions ol the true-com- 
pound leaf, which is produced only in the seeding- plant, or occasionally in 
the more advanced state in particular circumstances, or where plants have 
been injured. 
The great number of species of Acacia having this remarkable (eco- 
nomy in Terra Australis forms one of the most striking peculiarities of its 
vegetation. Nearly 100 species have already been observed ; more than 
half of these belong to the principal parallel, at both extremities of which 
they appear to be equally abundant ; they are however very generally dif- 
fused over the whole country, existing both on the north coast of New Hol- 
land, and at the south end of Van Diemen’s Island. But though the leat- 
less Acacia? are thus numerous and general in Terra Australis, they appear 
to be very rare in other parts of the world ; none of the Australian species 
are found in other countries, and at present I am acquainted with only seven 
additional species, of which five are natives of the intratropical Islands of 
the Southern hemisphere ; the sixth was observed in Owhyhee, and is said to 
be the largest tree in the Sandwich Islands; the seventh is Mimosa stellata 
of Loureiro, upon whose authority it entirely rests. 
The second order, Lomentace^e or Cjksalpineag, comprehends all 
the genera having perigynous stamina, a corolla whose <esti\ation is not 
