128 CRUCIFER^E. 



have been entirely swept away by Mr. Brown's masterly exposition of the 

 real nature and composition of the stigma, as well as of the placenta.* In 

 this family the two half-stigmas of different carpels are combined over the 

 placentae, just as those placentae are themselves formed by the junction of 

 the contiguous edges of two different carpellary leaves, that is, of the two 

 half-placentae of different carpels. As applied to Cruciferse, this view has 

 just been very satisfactorily reproduced by Moquin-Tandon and Webb, in 

 the article before cited, and entirely de novo on their part, as they were un- 

 acquainted with Mr. Brown's exposition of this subject until after their arti- 

 cle was prepared for the press. 



The structure of the flower and fruit in this strictly natural family is so 

 uniform, that it is unnecessary to repeat continually, in our detailed descrip- 

 tions, the characters which are common to the whole, or to which there are 

 few if any exceptions ; such, for instance, as the alternate leaves (to which 

 Dentaria offers the only exception) ; the indefinite racemose inflorescence ; 

 the absence of bracts and bractlets (of which the exceptions are noted where 

 they occur) ; the introrse 2-celled anthers ; the aestivation of the calyx and 

 corolla, which as to the former is imbricated with the anterior and posterior 

 sepals outside, as already mentioned, in all our genera ; and, as to the lat- 

 ter, the same genus or even the same individual exhibits both the imbri- 

 cated-convolute and the truly convolute modes. 



As at present known, this family comprises at least 1600 species, under 

 about 180 genera. Cruciferous plants are found in every part of the world, 

 but are most abundant by far in the northern temperate zone. There is a 

 larger proportion in the Old World than in the New. 



The sensible properties of the order are exemplified by its familiar escu- 

 lent and officinal representatives, such as the Mustard, Horseradish, Radish, 

 Cabbage, Turnip, Scurvy-Grass, &c. All have more or less of the volatile 

 acrid principle upon which their stimulant, rubefacient, and antiscorbutic 

 qualities, as well as the pungent flavor, depend. Diffused among abundance 

 of saccharine and farinaceous or mucilaginous matter, this acridity serves as 

 a wholesome natural condiment. Some Cruciferae, like the Rape, are culti- 

 vated for the fixed oil that abounds in the embryo of the exalbuminous seeds. 

 Many are prized for the beauty or fragrance of their flowers ; as the Wall- 

 flower, Stock, &c 



In a local Flora, it is most convenient to characterize the primary divisions 

 from the fruit, whether dehiscent, indehiscent and nucamentaceous, or lo- 

 mentaceous. In a general system, some characters taken from the seed and 

 embryo should doubtless have precedence ; but it is still uncertain which 

 should take the lead. For the present purpose it will suffice to dispose our 

 comparatively few genera according to the following conspectus. 



* In Plantce Javanica Rariores, part 2. 1840. p. 106-112, note. For an exposi- 

 tion of this view, see Gray's Botanical Text-Booh, ed. 1. p. 144 (1842), and ed.2. 

 p. 238 (1845). 



