CRUCIFERAE. 



' CRUCIFER/E. 



Character of the Order. Herbs with alternate, exstipulate leaves, cruci- 

 form flowers in terminal racemes or corymbs, and a pungent, acrid, watery- 

 juice. Sepals 4, deciduous. Petals 4, hypogynous, placed opposite each 

 other in pairs, their limbs spreading and forming a cross. Stamens 6 

 four of equal length placed in pairs opposite each other, the remaining 

 two, shorter, placed beneath them and opposite each other. Ovary of 2 

 united carpels, with 2 parietal placentae, separated by a membranaceous 

 partition ; style short or absent, often persistent ; stigmas 2, opposite the 

 placentae. Fruit a silique or silicle, usually 2-celled, rarely 1-celled, 1- to 

 many-seeded, dehiscent by the separation of the valves from the persistent 



placentae, or occasionally 

 indehiscent, and either 

 lomentaceous or nucu- 

 mentaceous. Seeds cam- 

 pylotropous, g e n e ra lly 

 pendulous, attached in a 

 single row to each side 

 of the placenta. Embryo 

 with cotyledons variously 

 folded on the radicle. 



This is a very natural 

 and easily recognized fam- 

 ily of plants, the cruciform 

 flowers (Fig. 105) and pe- 

 culiarly arranged stamens 

 (Fig. 106) serving for im- 

 mediate identification of the order. The identification of the genera is, 

 however, quite another matter. Here the characters are taken from the 

 pods and seeds, and in some instances are. to the beginner at least, very 

 perplexing. 



All the crucifers possess, to a greater or less extent, acrid and irritat- 

 ing properties, but none of them are positively poisonous. The acrid 

 principle is usually of a volatile character, somewhat dissipated in drying 

 and entirely so by boiling. Though generally present in all parts of the 

 plant, it is often most concentrated in the seeds, and may be obtained 

 from many of them by distillation in the form of a volatile oil. Whatever 

 of medicinal importance the order may have is undoubtedly due to the 

 acrid principle present, and this appears to act merely by virtue of its 

 stimulant and irritant properties. Hence all statements attributing spe- 

 cific virtues to any plant of the order should be viewed with suspicion. 

 There is no one order in the vegetable kingdom of more strongly marked 



FIG. 105. Form of flower com- 

 mon to the Cruciferae. 



FiG. 106. Arrange- 

 ment of stamens com- 

 mon to the Cruciferae. 



