M. A. Chatin on the Anatomy of the Rhinanthacese. 331 



XXV. — On the Anatomy of the Rhinanthacese, considered in its 

 relations with the classification of these plants. By A. Chatin *. 



It can no longer be doubted that Anatomy can and must inter- 

 vene in Botany, as it has long done in Zoology, to fix the posi- 

 tion of orders, families, genera, and frequently even of species 

 of plants in the natural system, and to complete their diagnosis. 

 The researches which I have just completed upon the Rhinan- 

 thacea, an important family, the parasitism of which was not 

 suspected before the interesting and unexpected observations of 

 M. Decaisne f, bring in support of this opinion an amount of 

 new facts, which, it seems to me, should attract the attention of 

 those naturalists who take an interest in the means of perfect- 

 ing the natural system, and especially that of those who occupy 

 themselves with descriptive Botany. 



As essential anatomical characters of the order Rhinanthacea, 

 I shall indicate in the stem, the vessels never entirely united into 

 bundles, and the want of the fibro-cortical system, or at least of 

 cortical prosenchyma exterior to the fibrous tissue properly so 

 called ; in the rhizome, the constant existence of the organ itself, 

 always anatomically determinable, the absence of true spiral 

 vessels, and the vessels never approximated in groups ; in the 

 leaves, the epidermic cells which are always chromuliferous, al- 

 though furnished with numerous stomata, and the vessels gene- 

 rally neither prismatic nor pressed together. 



The natural anatomical character is completed by the habitual 

 absence of medullary rays in the rhizome, and of the fibro-cortical 

 body in the stem, by the medullary sheath and proper woody 

 stratum not being confused, by the leaves with the epidermic 

 cells almost always with sinuous side-walls, and with the paren- 

 chyma homogeneous towards the two faces ; and, lastly, by the 

 presence of capitate glands of 1 to 4, rarely 8 cells, as in many 

 true Scrophulariacece, 



The RhinanthacecB have very great affinities with non-parasitic 

 plants not belonging to the same family. However, to the 

 morphological characters which distinguish them from the Sera- 

 phulariacece, and which appeared to the illustrious Laurent de 

 Jussieu sufficient for their separation, we must add their para- 

 sitism, the constant absence of medullary rays in the stems, and 

 that of the fibro-cortical bundles. 



The families of parasitic plants with which the RhinanthacecB 

 have the most analogies, both anatomical and morphological, 

 are the Epirhizanthacece, the Orobanchece, and the Monotropece. 



* Translated from the Coraptes Rendus de TAcademie des Sciences de 

 Paris, 2nd March, 1857, p. 470. 



t Comptes Rendus, 12th July, 1847. 



