AN ACCOUNT OP THE GENUS AKGEMONE. 177 



as A. Georfjiana Lestiboudois's A. alba (Hornemann's A. alhifiora)', 

 and A. Gray described in 1845 as A. hispida a plant that is perhaps, 

 as most American botanists tliiiak, not specifically separable from 

 A. plati/cenis. In 185i A. fnUicosa of Thurber, the only species 

 whose validity it is impossible to dispute, was published. In 1855 

 Durand and Hilgard published as A. munita a plant that is certainly 

 only A. hispida of Gray, and in 1886 Greene published as A. 

 corymhosa one that is perhaps only A. inteniiedia of Sweet. Besides 

 the forms enumerated there are two others which are more or less 

 distinct : one is from the Sandwich Islands ; this I have in the 

 present paper referred to A. alba, but, perhaps rightly, Mr. Nuttall 

 has proposed for it specific rank, under the name A. ijlauca; another 

 from Northern Mexico has been issued by Mr. Pringle as A. platy- 

 ceras, an impossible identification ; this latter I have referred, as a 

 temporary measure, to A. intermedia ; but it is perhaps deserving of 

 specific rank, and, if so, may be conveniently known as A. steno- 

 p)etala. 



There are thus at least eleven Argemones which are easily 

 distinguishable, and which admit of more or less satisfactory 

 definition. And, as a study of their bibliography and a perusal of 

 the notes appended to their systematic diagnoses will show, it is 

 not improbable that even more forms may yet be satisfactorily 

 differentiated. But these forms are not by any means all of equal 

 rank ; in place, therefore, of giving in every case a specific value 

 to their characters, I have only allowed specific rank to each of the 

 separate groups of forms, assigning to the different Argemones of 

 each group a merely varietal position, and leaving it to authors 

 who can make a careful study of the genus on the lines adopted by 

 Mr. Greene in his study of the genus Eschscholzia, to assess at its true 

 worth the claim of each individual form to separate recognition. 

 In the three most important works in which the genus has been 

 defined,* the number of species admitted has been five or six ; this 

 estimate is apparently based on the purely compilatory and un- 

 critical revision of the genus by Walpers,+ for in the only serious 

 attempt that has been made to review the species of Aryemone 

 Otto and Dietrich | have recognised eight. It is significant, too, 

 that these last-named authors are the only botanists who have not 

 given way to the tendency, against which Sir WiUiam Hooker§ 

 warned botanists to be careful, of relegating to A. viexicana any 

 form that it is difficult to localise. When, therefore, it is pointed 

 out that the number of species recognised in this paper is only 

 six, and that thus it is in accordance with the estimates referred 

 to, care must be taken not to conclude that the treatment here 

 adopted is in any way intended to distort the genus so as to 



* Bentham & Hooker, Genera Plantarum, i. 52 ; Baillon, Histoire des 

 Plantes, iii. 113 ; Prantl & Kiindig in Engler, Natilrlichen Pjlanzenfamilien, iii. 

 pt. 2, 141. 



t Walpers, Rcpertorium, i. 109 (1842). 



I Otto & Dietrich, AlUjemeine Gartenzeitimg, i. 298 (1833). 



§ Bot. Miscell. ii. 207 (1831). 



Journal of Botany. — Vol. 33. [June, 1895.] n 



