14 



Geography. All inhabitants of the marshes of North America. 



Properties. The root of the May Apple, Podophyllum peltatum, is 

 one of the most safe and active cathartics that is known. Barton, 2. 14. 

 JefFersonia is also purgative. Decand. 



Examples. Podophyllum, Jeftersonia. 



IX. CRUCIFER^. The Cruciferous Tribe. 



Crucifer^, Juss. Gen. 237. (1789) ; Dec. Mimoire sur les Cruciferes (no date) ; St/sl. 

 2. 130. (1821) ; Prodr. 1. 131, (1824) ; Lindl. St/nops. 20. (1829.) 



Diagnosis, Polypetalous dicotyledons, with hypogynous tetradyna- 

 mous stamens. 



Anomalies. Schizopetalum has 4 cotyledons ; sometimes the petals 

 are abortive. 



Essential Character •S'ejja/s 4, deciduous, cruciate. Petals 4, cruciate, alter- 

 nate with the sepals. Stamens 6, of which two are shorter, solitary, and opposite the 

 lateral sepals, occasionally toothed ; and four longer, in pairs, opposite the anterior and 

 posterior sepals ; generally distinct, sometimes connate, or furnished with a tooth on the 

 inside. Disk with various green glands between the petals and the stamens and ovarium. 

 Ovarium superior, unilocular, with parietal placenta; usually meeting in the middle, and 

 forming a spurious dissepiment. Stigmata two, opposite the placentae. Fruit a siliqua or 

 silicula, 1-celled, or spuriously 2-celled ; 1- or many-seeded ; dehiscing by two valves sepa- 

 rating from the replum ; or indehiscent. Seeds attached in a single row by a funiculus to 

 each side of the placentae, generally pendulous. Albumen none. Embryo with the radicle 



folded upon the cotyledons Herbaceous plants, annual, biennial, or perennial, very seldom 



suffruticose. Leaves alternate. Flowers usually yellow or white, seldom purple. 



Affinities. This order is among the most natural that are known, 

 and its character of having what Linnsean botanists call tetradynamous sta- 

 mens is scarcely subject to exception. It has a near relation to Capparideae, 

 Papaveracese, and Fumariaceas. With Capparideae it agrees in the number 

 of the stamens of some species of that order, in the fruit having two placentae 

 and a similar mode of dehiscence, and in the quaternary number of the divi- 

 sions of the flower. To Papaveraceae it approaches in the number of the 

 petals, an unusual number to prevail in dicotyledonous plants, and again in 

 the structure of the fruit of some genera of that order, such as Glaucium and 

 Chelidonium. With the siliquose-fruited Fumariacese it has much analogy, 

 and even with the whole of that order in the number of its petals, supposing 

 the common opinion of the nature of the floral envelopes of Fumariacea; to be 

 correct, or in the binary division of its flower, from which the quaternary is 

 only a slight deviation, upon the hypothesis I have suggested in speaking 

 of that order. 



Cruciferge may be said to be characterised essentially by their devia- 

 tion from the ordinary symmetry observable in the relative arrangement 

 of the parts of fructification of other plants, — deviations which are of a very 

 interesting nature. Their stamens are arranged thus : two stand opposite 

 each of the anterior and posterior sepals, and one opposite each of the lateral 

 sepals ; there being 6 stamens to 4 sepals, instead of cither 4 or 8, as would 

 be normal. Now in what way does this arise? is the whorl of stamens to be 

 considered double, one of the series belonging to the sepals, and one to the 

 petals, and, of these, one imperfect? I am not aware of any such explana- 

 tion having been offered, nor do I know of any better one. It appears to me 

 that the outer series is incomplete, by the constant abortion of the stamens 

 belonging to the anterior and posterior sepals. But it is in their fruit that 



