GROUP - V. ANGIOSPERM.E ; DICOTYLEDONES. 



535 



nating with the four sepals as if the latter formed one whorl; 

 there are, however, three perianth-whorls, as in the two preceding 

 families ; but whereas in them only the 

 outermost whorl is sepaloid, in this family 

 the two outer whorls are sepaloid, and the 

 innermost, which alone is petaloid, is a 

 whorl consisting of four instead of two mem- 

 bers. The two outer stamens are lateral, 

 as in those families ; the two inner ones, 

 which in most Fumariaceae are apparently 

 divided, are here duplicate, having longer 

 filaments (Fig. 348 B b b) than the outer 

 ones (a) ; hence they are tetradynamous. There are usually four, 

 sometimes more, nectaries at the base of the stamens (Fig. 348 B d). 

 The ovary consists of two carpels with the ovules in two longi- 

 tudinal rows on the connate margins of the carpels ; these two 

 parietal placentae are connected by a membranous growth which, 

 as it is not formed of the margins of the carpels, must be regarded 



o. 317. Diagram of the 

 flower of Cruciferae. 



Fi 343.- Flowers, fruits, and embryos of various Cruciferas. A Flower of Brassica (nat. 

 sizeT's pedicel; l:k calyx; c corolla. B The same after removal of the perianth ( 

 ma<O a a the two outer short stamens ; I the four longer inner ones ; / the ovary ; 

 stigma ; d gland. C Siliqua of Brassica ; v dissepiment. D Angustiseptal ailicuU ol 1 

 E Latiseptal silicula of Draba. D* and * Diagrammatic transverse section of the pi 

 ing v dissepiment s seed. F indehiscent silicula of Isatis. G Jointed siliqua of Ruj./i,i.n.* 

 KapJicmistrum : g style ; I II separate segments. H-K Diagrams of differently-fold 

 embryos, with transverse sections : r radicles ; c c cotyledons. 



