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pie or pinnate, covered with pellucid resinous dots. Flaicers axillary or terminal. All the 
parts aromatic. 
Anomalies. Some of the genera are monopetalous, others have the carpels in great 
part distinct. Empleurum has no petals. Dictamnus and some others have irregular 
flowers and more ovules than 2. According to Brown, there is a New Holland genus, with 
perigynous stamens, 10 segments of the calyx, 10 petals, and indefinite stamens. 
Affinities. There are two principal divisions in this order ; the one 
Ruteae proper, which have seeds containing albumen, and a fruit the sarco- 
carp of which is said not to separate from the endocarp ; the other Diosmeae, 
whose seeds have no albumen, and whose sarcocarp and endocarp divide into 
distinct bodies when the fruit is ripe. But Aug. de St. Hilaire (FI. Bras. 1. 
74.) suspects that those two parts are equally separable in Ruteae, and that the 
specimens in herbaria which have been found otherwise were gathered before 
their fruit was quite ripe. At all events the difference is too slight for the 
character of an order ; and the absence or presence of a small quantity of al- 
bumen can no longer be insisted upon now that so many cases of its absence 
or presence in the same order are known ; indeed, Hortia, a Diosmeous genus, 
has albumen, according to Aug. de St. Hilaire. Ruteae are allied to Zygophyl'- 
laceae through Peganum, which A. de Jussieu actually stations here, although 
its stipulate leaves, destitute of pellucid dots, seem to determine its greatest 
affinity to be with Zygophyllaceae. A. de Jussieu, from whose excellent me- 
moir upon Rutaceae I have borrowed the greater part of my remarks upon 
Rutaceae, Zygophyllaceae, Xanthoxylaceae, and Simarubaceae, speaks thus of 
Diosmeae. (Mem. p. 19.) : — 
“ Diosmeae are a group to which Mr. Brown gives that name, with the 
exception, however, of some of the genera wffiich he refers to it ; and they are 
that by the characters of which botanists have generally defined Rutaceae. 
It is not necessary to describe the floral envelopes, the stamens, the disk, or 
the structure of the seed, because these parts vary according to the sections, 
which are in part characterised by their differences, and they will be better 
examined in their respective places. But it is important to understand the 
ovaries, and especially the pericarp, the structure of which is very characteristic. 
The ovaries, whether combined by their central axis, or more or less distinct, 
always contain 2 ovules ; if 4, or sometimes but 1 are found, this occurs only in 
genera stationed at the extreme limits of the group. They are collateral, or 
more frequently placed one above the other, and then one is usually ascending, 
and the other suspended. This position, which at first sight appears singular, 
is very natural ; for the ovary is usually pierced by the vessels of the style 
only in the middle, and it is at that point that the two ovules are inserted, 
both at nearly the same height. If, therefore, they are placed one above the 
other, it is indispensable that one should ascend, and the other descend. These 
ovules may be considered peritropal, rather than either ascending or suspended, 
or, in other terms, attached by their middle rather than by either extremity.” 
— “ If the ovary of a Diosmea is divided across, its coat will be found to 
consist of two layers, the outer rather the most fleshy, and the inner thin or 
almost absent on the side next the axis, the side which is traversed from bot- 
tom to top by the vessels of the peduncle. These vessels, at a certain height, 
meet those of the style, either at the point of its insertion or below it ; united 
to these, they penetrate the cavity of the cell, the shell of which they pierce, 
and there form funiculi, to which the ovules are attached. Thus far the struc- 
ture of Diosmeae is little different from that of other Rutaceous plants. But 
this becomes modified as the ovary advances towards the state of fruit. The 
endocarp hardens by degi*ees, and at the same time separates from the sarco- 
carp. Its form resembles that of a bivalve shell, and may be more especially 
compared to that of a mussel ; it presents two extremities, one superior, the 
