THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY 



No. 135. DECEMBER 1847. 



XXXV. — Observations on the Structure of the Fruit of the 

 Cruciferse. By L. C. Treviranus*. 



Among the Cruciferse some years since introduced into German 

 gardens, JEthionema heterocarpum, Gay. is remarkable from the 

 fact that in certain individuals occur two-celled many-seeded 

 and one-celled single-seeded silicles. The former are flat upon 

 the upper side and somewhat vaulted on the under, and in cor- 

 respondence with this the upper border of the septum is straight, 

 while the under has a convex form. In the latter the under side 

 is strongly excavated, rendering the whole silicle almost globular ; 

 the keel is wanting on this deepened under side, and the solitary 

 seed lies, as in Isatis and Tauscheria, directly in the middle of 

 the silicle, being attached at the summit of its cavity. This 

 species therefore connects certainly the genus jEthionema with 

 Tauscheria, only in Tauscheria the enlargement of the silicle is 

 above, while that of JEthionema heterocarpum occurs on the under 

 side. If however Tauscheria is to stand, another genus, namely 

 Campyloptera, Boiss.f, cannot I think be retained, since the plants 

 on which it is founded appear to be specimens of jEthionema 

 heterocarpum, bearing no other fruit than the one-seeded kind 

 above described. 



It is difficult to say what causes this remarkable deviation in 

 some silicles from the normal structure of the others. It cannot 

 be called a monstrosity, since the seed of the one-celled silicle 

 is just as perfect as those which the two-celled yield ; the flowers 

 also which produce the former are not less perfectly organized 

 than those from which the two-celled fruits come. I have been 

 induced therefore to institute some researches into the structure 

 of the fruit of the Cruciferse, and albeit these have not led to the 

 wished-for elucidation, I will nevertheless publish some of the 

 results, which may perhaps possess more general interest. 



* From the Botanische Zeitung, June 11th and 18th, 1817. Translated 

 by Arthur Henfrey, F.L S. 



t Ann. d. Sc. Nat. 2 se>. xvii. 194. 

 Ann. $ Mag. N. Hist. Vol. xx. 26 



