414 



ORDER RUTACE^E, OR RUE TRIBE. 



fleshy ring surrounding the ovary. Upon this ring is seated the 

 ovary, which consists of four carpels united into one mass. These 

 do not stand upright, however, as they usually do ; but spread 



FIG. 153. GARDEN RUE. A, magnified flower deprived of petals; a, fleshy ring 

 from which the stamens arise ; B, section of ovarium ; a, the gynobase ; 6, the placentae. 

 C, a sjcd-vessel after bursting; a, the gynobase. 



away from each other at the base, being arranged on the sides of 

 a conical disk, which rises up between them, but is not continued 

 into the style. This disk is termed the gynobase, or base of the 

 female organs (.484.) The style is single, being formed by the 

 adhesion of those of the several carpels ; but it separates at the 

 top into four stigmas. The seed-vessel, when ripe, splits into 

 four valves, leaving the thick hard gynobase in the centre. The 

 number of seeds contained in each varies considerably, but is 

 almost always less than that of the ovules. In the common Rue, 

 there are about four ovules in each cell ; but only one of these is 

 developed into seed. In others the ovules and seeds are more 

 numerous. One genus (Correa) of this order presents an inte- 

 resting anomaly, of a similar character to that which has been 

 mentioned as occurring in the order TropceolecB ; the petals cohere 

 together into a tube, so that the plant is really Monopetalous ; 



