natural Family of Vlants called Compositce. 123 



pappus of the male flower only. Its species are Gnapkalium dioi- 

 cum Linn., alpinum L., cavpaticum Wahlenberg, plaiitagineiiin I^., 

 and G. margaritaceum L. 



Tlie second tribe, consisting of Gnaphalium Leoitlopodium and 



Obs. Gnaphalium margaritaceum, which I have referred to this genus, was first described 

 by Clusius ; from whose account it appears to have been introduced into the English gar- 

 dens from America towards the end of the sixteenth century. 



It has ever since been very generally cultivated, as an ornamental plant, both in this 

 country and on the continent of Europe ; and has a place in several of the European Floras, 

 as well as in those of North America. It is surprising, therefore, that hitherto the male plant 

 only should have been observed, uniformly, however, considered as hermaphrodite, except 

 by M. Cassini, who in his first memoir on SynanthercB (in Journal de Physique, tome Ixxvi. 

 p. 200) suspects it to be male, from the imperfect appearance of the ovarium. 



That this species of Gnapkalium is really dioecious, I learned several years ago from 

 the inspection of !f specimen of the female plant in the Herbarium of Sir Joseph Banks, 

 who found it on the banks of the Rymney in Glamorganshire, where the plant was first 

 observed by Lhwyd. I have since received several specimens of both sexes from Mr. Bi- 

 cheno, to whom 1 had mentioned this fact, and who obligingly undertook to observe 

 the different states of the plant in the same place, where it seems to be really indigenous. 

 I have never been able to discover any female florets in the circumference of the capitu- 

 lum of the male plant ; but in the centre of the female capitulum I have always found 

 two or three imperfect male florets, whose antheroe, although cohering and of the usual 

 form, appear to be destitute of pollen. 



The separation of sexes in a still more common plant of this class, namely, Serratula 

 iinctoria, has been equally overlooked. 



All the authors who have noticed this species, which is included in almost every Euro- 

 pean Flora, as well as in more than one recent Monograph of the genus, have considered 

 it as hermaphrodite, while it really belongs to Polygamia dioecia, or has its perfect sexual 

 organs on diffierent plants. The hermaphrodite plant, apparently perfect, but which I 

 believe very seldom ripens seed, is well figured by Schkuhr (in Botanisches Handbuch, 

 tab. 234) ; and the female, whose stigmata are remarkably developed and undulated, 

 while the antherae are evidently imperfect, and which generally produces ripe seeds, is 

 represented in English Botany (tab. 38), in Flora Danica (281), and probably also in 

 Svensk Botanik (170). For my knowledge of this fact respecting Serratula tinctoria I 

 sm indebted to the Rev. Robert Bree of Camberwell, who pointed out to me both its 

 «tates, which he was then disposed to consider as distinct species. 



u 2 Leonto- 



