348 CISTALES. [Hypogynous Exogens. 



Alliance XXVII. CISTALES.— Tub Cistal Alliance. 



Diagnosis. — Hypogynous Exogens, with monodichlamydeous flowers, parietal or sutural 

 pilacentce, and a curved or spiral embryo, with little or no albumen. 



If we consider the Violal Alliance to be closed by Turnerads, that of Cistals will 

 necessarily commence with Rock Roses, which have much the habit of the foi*mer, but 

 which are distinctly separated by their convolute embryo and orthotropal seeds, to say 

 nothing of divers other characters. If the Rock Roses are regarded as an Order with 

 indefinite stamens, they will join Cappaiids, but if the genera with definite stamens are 

 assumed to be the point of depai*tvire onwards, then it is into Ci-ucifers that the fine will 

 pass. The parietal placentation of Rock Roses is universal ; and though the number of 

 placentae is never reduced to two, yet if Fig. ccxli., 2, in the following page has one 

 of its placentae removed and the other two brought into contact, we shall have the sUicie 

 of a Crucifer. Tliex'e is no distinct passage from Cinicifers into Weldworts, which may 

 be regarded as being an anomalous form of Capparids rather in dii'ect succession from 

 Crucifers ; but to Capparids themselves Crucifers pass by the w hole division of Cleomese 

 among the former, some of wiiich are actually hexaudi'ous. The stipitate fruit of Cap- 

 parids brings us easily to Sterculiads in the next Alliance. 



Supposing these views to be just, then the mutual relation of the Orders included in 

 the Cistal Alhance may be thus expressed : 



Turneracece. — Cistacese : Brassicaceae : Capparidacese. — Stcrculiacece. 



IlesedacecB. 



Natural Orders of Cistals. 

 Stamens not tetradynamous, generally indefinite. Floicers^ or \ 

 ^. Seeds with albumen. Fruit closed icp . . . j 

 Stameois tetradynamous. Floimrs^ 123. Brassicacejs. 



122. ClSTACE^. 



Stamens not tetradynamous, definite. Flotoers not tetramcrous. "I 



124. Resedace^. 



Seeds ivithout albumen. Fruit usually op)en at the point 



Stamens not tetradynamous. Floioers X/. Seeds witho%U albumen. I , ^ t n 



Fruit closed up ... ^. ... . } 125. Capparidace^. 



