Mr. J. Miers on Ephedra. 139 



of the lower branchlets, while all the upper ones exhibited male 

 flowers only; but I was unwilling to place much reliance on 

 that circumstance at this distance of time, as all my specimens 

 were lost. I have, however, lately noticed a confirmation of this 

 fact in a specimen, now existing in the Hookerian herbarium, 

 of the same species, where most of the ramifications have their 

 floral branchlets terminated by ripe fruits, while in a lower part 

 is another branchlet charged with a spikelet of male flowers. 

 Kunth also corroborates a similar occurrence in Ephedra ameri- 

 cana : in that species, he states that each axil produces a cluster 

 of four spikelets, three of which consist of male florets, while the 

 other contains two female flowers ; for he adopted the view of 

 Richard in considering the pericarp of each achenium as the 

 indurated perigonium, and the enclosed seed with its tubillus as 

 the ovary surmounted by its style. It is still a matter of doubt 

 whether the two achenia generally associated in the apex of a 

 spikelet are produced from one or two florets. I am inclined to 

 think the latter, because it is more in analogy with the position 

 of the male florets. Meyer describes four species from Southern 

 Europe and Mauritania, where the fruit is constantly solitary in 

 each spikelet : this, perhaps, is merely the result of the abortion 

 of one of the florets. 



Careful observations on the progressive growth of the plants, 

 made in their living state, are required to clear up these several 

 doubts, and to complete the history of Ephedra. The following- 

 diagnosis of the genus is based wholly upon my own observations 

 of the South- American species here described. 



Ephedra, Tournef. — Flores unisexuales ; sed dubitandum est, si 

 sexus singuli in diversis plantis, vel in diversis ramis, vel in 

 eadem spica orti sint : certissime <$ in axillis spicarum enati, 

 mox decidui, ? semper terminales et forsan in eadem spica 

 tardius oriundi. — Flores <Jin spica amentiformi imbricato- 

 involucrata plurimi; involucellum singulum bracteiforme imo 

 cum opposito in vaginam brevem coalitum, ovatum, erectum; 

 involucella hoc modo per paria nexa, decussatim imbricata et 

 4-faria, singula 1 -flora. Perigonium intra quodque involucel- 

 lum unicum, e basi ortum, petaloideum, coloratum, turbinato- 

 tubulosum, compressum, limbo 2-labiato, labiis (antico et 

 postico) rotundatis, sestivatione imbricatis, posteriore exteriore, 

 mox deciduum. Stamina monadelpha, cum perigonio deca- 

 dentia ; filamenta in columnam fistulosam compressam apice 

 dentatam aut breviter fissam perigonio sequilongam vel lon- 

 giorem connata ; anthera 3 ad J 2, tubi dentibus vel filis bre- 

 vissimis crebriter basifixse, ovatse vel oblongse, erectse, 2-lobse, 

 2-locellatse (lobis sine connectivo collateraliter adnatis), poris 



