132 • 



or stalked, its lobes equal to the number of petals, or fewer ; ovules twin and collateral, or 

 one above the other, very rarely 4 ; style single, occasionally divided towards the base into 

 as many parts as there are lobes of the ovarium ; stigma simple or dilated. Fruit consisting 

 of several capsules, either cohering firmly or more or less distinct ; the endocarp separating 

 entirely from the sarcocarp, which is 2-valved ; the former 2-valved also, the valves dividing 

 at the base, but connected by a membrane which bears the seeds. Seeds twin or solitary, 

 with a testaceous integument ; embryo with a superior radicle, which is either straight or 

 oblique, and cotyledons of variable form; albumen none — Trees .or shrubs, very rarely 

 herbaceous plants. Leaves without stipulae, opposite or alternate, simple or pinnate, 

 covered with pellucid resinous dots. Flowers axillary or terminal. All the parts aromatic. 



Affinities. M. A. de Jussieii, from whose excellent memoir upon 

 Rutaceae I have borrowed the greater part of my remarks upon Rutacece, 

 Zygophyileae, Xanthoxylese, and Simarubaceae, speaks thus of Diosmeae 

 (Mm. p. 19.): — 



" Diosmeae are the group to which Mr. Brown gives that name, with 

 th'e exception, however, of some of the genera which he refers to it ; and 

 they are that by the characters of which botanists have generally defined 

 Rutacese. It is not necessary to describe the floral envelopLS, the stamens, 

 the disk, or the structure of the seed, because these parts vary according 

 to the sections, v^'hich are in part characterised by their ditFerences, and they 

 will be better examined in their respective places. But it is important to 

 understand the ovaria, and especially the pericarp, the structure of which 

 is very characteristic. The ovaria, whether combined by their central axis, 

 or more or less distinct, always contain 2 ovula ; 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 indispen- 

 sable 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 ovarium 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 bottom 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 funicidi, to which the ovula are 

 attached. Thus far the structure of Diosmesc is little different from that 

 of other Rutaceous plants. But this becomes modified as the ovarium 

 advances towards the state of fruit. The endocarp hardens by degrees, 

 and at the same time separates from the sarcocarp. 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 other inferior, two 

 lateral faces which are more or less convex, and two edges more or less 

 acute, which unite them, the one external, the other internal. The two 

 valves are woody and touch at the edges, except perhaps at a part of their 

 inside where they are separated ; this space is filled by a membrane which 

 passes from one to the other : it is either slightly fleshy, or, which is more 

 common, extremely thin, thickened in the middle by the passage of the 

 vessels of the seed which penetrate it; and as, after having pierced it, they 

 are almost immediately inserted into the stud, (he latter appears to be 

 actually bonio by the membrane itself. When the fruit is perfectly rif)c, 



