138 Mr. J. Miers on Ephedra. 



invariably at the base of the tubular portion of the perigonium, 

 as in Ephedra, and often the filaments are monadelphously con- 

 joined at their base. In the tribe Forskohlece the involucels of 

 the flowers are combined into an annular cup^ as in Gnetum ; 

 sometimes two involucels, united at the base, contain one or two 

 florets, and then the solitary stamen is fixed in the base of the 

 perigonial tube, without any vestige of an ovary, as in Gnetum, 

 I have stated these numerous points of coincidence in order to 

 show that, when we take into consideration the sum of their 

 characters respectively, a greater approximation will be found to 

 exist between these two families than has been imagined : in 

 the present imperfect state of our knowledge, their juxtaposition 

 in the system cannot be safely established ; for the Gnetacece 

 require a more careful examination. Much additional informa- 

 tion may be expected from the promised description, by Dr. 

 Hooker, of the new and curious genus TVelwitschia, which, I 

 have no doubt, will tend greatly to elucidate the question of the 

 true affinities of this family. 



Meyer has classed the difi'erent species of Ephedra in two 

 sections, — the one, Plagiostoma, where the summit of the tubillus 

 is obliquely ligulated or unequally two-lobed ; the other, Disco- 

 stoma, where it is truncated or enlarged in the form of a disk, 

 the latter section comprising only two species, which are of 

 South-American origin, E. Tweediana and E. americana. On 

 referring to his drawing of the former species (Mem. Acad. St. 

 Petersb. tom. v. pi. 7. fig. 9), we find there a representation of 

 this tubillus, marked h, which shows no approach whatever to a 

 disciform shape ; and in regard to the latter species, which Meyer 

 does not appear to have seen, Kunth describes its tubillus as he 

 conceived it to be, a " stylus subulatus exsertus, stigma simplex ;" 

 and Richard defines the same as "rectus, tubulosus, ostiolo 

 oblique sub-4-lobo." In all the specimens of E. Tweediana that 

 I have seen, especially in those collected by myself, the tubillus 

 is straight, in no degree enlarged at the apex, and generally 

 lacerated ; but, when uninjured, I have found it shortly 2-fid, 

 with two small erect rounded lobes, differing in no respect from 

 what is observable in his section Plagiostoma, I therefore con- 

 sider that such a division of the genus, founded upon the cha- 

 racter assumed, is not maintainable. 



I have expressed a doubt [ante, vol. ix. 426) of the truth of 

 the general belief that in Ephedra the flowers are dioecious, that 

 is to say, that the male and female flowers are always upon di- 

 stinct plants. I have stated the impression entertained by me 

 when in Chile, that both sexes exist on the same plant, if not in 

 the same spikelets : in support of this, my drawing of Ephedra 

 hracteata, made nearly forty years ago, showed fruits upon one 



