151 



Fournier cites Robert Brown' for this species and gives it as a synonym for W. 

 mollis J. Smith, as docs Hemslcy- also; but the very marked difference in the struc- 

 ture of the involucres is of itself a sufficiently good character to separate the two — 

 W. mexicana and W. mollis — absolutely. 



WOODWARDIA. 



Woodwardia radicans J. E. Smith, Mem, Acad. Tor. 5 : 412. 1793. 



Near Santa Teresa, August 12 (No. 2214). The American forms of this species have 

 been considered as distinct species, or at least as varietal, but there appears to be 

 no really good reason for separating them from the European. 



A PROPOSED REARRANGEMENT OF THE SUBORDER AGAVEAE. 



The accepted distinctions separating Agave and its allies are not 

 altogether satisfactory. 



I am led to propose the following arrangement after a study extend- 

 ing over several years. Besides the National Herbarium, I have had 

 almost daily access to the rich collections of the Washington Botanical 

 Garden, as well as four months' study in Mexico, where I had an oppor- 

 tunity of seeing thousands of these plants growing under their natural 

 conditions. In this connection 1 ought to state that I brought back OS 

 specimens for the herbarium and 44) living plants, more than half of 

 the species represented by the latter being new to cultivation. In 

 Mexico I had great difficulty in determining the genus to which a num- 

 ber of my plants of this group belonged. For instance, I found that 

 Polianthes was said to have a "lax simple spike," Prochnyanthes a 

 "lax raceme,' 1 and Bravoa an "inflorescence laxly spicate or racemose." 

 Prochnyanthes was found, however, with nearly sessile flowers, while 

 Polianthes has often shortly pediceled flowers or even a paniculate 

 inflorescence. In fact, there is no difference in the inflorescence of 

 these three genera; the roots, stems, leaves, are also all on the same 

 plan, and the habit and habitat are similar. The only grounds for 

 generic separation lie in the perianth, and I have sometimes felt that 

 these were not sufficient. Indeed, any such distinction seems to break 

 down between the first and last. The close relationship of these three 

 genera has been observed by others. Mr. Baker arranged them one 

 after the other, although he has not brought out clearly the real differ- 

 ence that exists between them, and places Prochnyanthes between 

 Polianthes and Bravoa. It must be remembered, however, that most 

 of the species have heretofore been known only from single specimens. 

 The point at which my results seem to differ most from those of others 

 is in the placing of the herbaceous species of Agave nearer the above 

 than to Agave proper. It is remarkable that the herbaceous Agaves 

 have not been united into an independent genus before. 



It is true that single species, four in all, have been made the types 

 of as many distinct genera, but the peculiar and uniform group com- 

 posed of some 15 species has not been segregated. The relationships 



1 In Wall. PI. Asiat. Kar. 1:42. - Biol. Cent. Am. 3 : 595. 



