21 6 NATURAL HISTORY OF PLANTS. 



14. The fruit of the Crucifers is termed siliqua or silicule according 

 as it is long or short. 1 To really deserve these names it must be dry 

 and dehisce longitudinally. But often it does not open, or separates 

 transversely into one- or many-seeded joints. It is then usually not 

 quite dry during the days before maturity. A woody or even bony 

 stone may be distinguished, surrounded by a thin layer of fleshy or 

 suberous mesocarp, which later on dries leaving the fruit " nuca- 

 mentaceous." The true siliqua or silicule dehisces into three parts, 

 {a) a frame (Fr., cadre) or replum, corresponding to the placentas, 

 whereon is stretched a false septum springing from them, 2 complete, 

 or incomplete and perforated, fenestrated, or even reduced to its 

 edges, membranous and translucent, even or veined, 3 or rarely thick 

 and rigid, dividing the ovary and fruit into two lateral half- or 

 false-cells ; (6) two lateral valves, varying in form like the siliqua, 

 nearly flat or more or less tumid gibbous or carinate, smooth 

 wrinkled or muricate externally, without visible veins, or with a 

 midrib and lateral veins of variable prominence, either free or con- 

 nected by simple or anastomosing venules. All these details 

 generally vary from genus to genus. The apex of the fruit may 

 present prominences of diverse origin. Two correspond with and 

 prolong the placentas ; they may be simple, or bifurcated as in Paro- 

 linia. Others alternating with these correspond with the apices of 

 the carpellary leaves. And some answer to a variable projection of 

 the back of the valves, as in Tetracme or Jnastatica, and form points, 

 or scales more or less dilated transversely. It will be seen below 

 that the most important character is taken from the general form of 

 the cross section of the fruit, according as its breadth is the same 

 in all directions, or compressed parallel with or perpendicular to the 

 septum. Its edges are then often more or less turned off, and keeled 

 or with entire, incised, or even fenestrated wings, as in Thysanocarpus. 

 The apex of the fruit maybe obtuse or prolonged into a beak formed 

 by the style or its persistent base ; and this beak may remain 

 attached or fall off at the base ; a character which may be used in the 

 distinction of genera or subgenera. 4 



1 See p. 199, note 4. superadded in certain cases. (Fotten., in Bull. 



- See Bayek, Organog., 212. Soc. Bot. de Fr., xi. 237, 2S8.) 



3 It is formed of one or more nearly parallel 4 The fruits of Morisia and Oeococcus are 



layers of cells, with peculiar elongated fibres peculiar in ripening under ground. 



