﻿AGAVE MACROACANTHA AND ALLIED EUAGAVES. 241 



1880, was sent to Dr. Ross and likewise identified with his 

 new species, which was an openly paniculate Euagave, with 

 dive green Aowers of a general resemblance in3ividua% 

 to those figured by Hooker for A. Besseriana 



No later publications throw 



any additional light on this 



group of species, though some of them have received passmg 

 mention or encyclopaedic treatment. 



Summarized, the literature shows that Zuccarini's three 

 species. Agave rmcroacanthxi, A. pugioniformis and A Kar- 

 wmskii, with the others here associated with them not defi 

 nitely known to occur spontaneously outside of the region 

 between Puebla and Mitla, constitute a natural subdivilon 

 of Mr. Baker s group "Rigidae," the species of which, properly 

 hmited, are normally pamculate in inflorescence and likewise 

 with the flowers, capsules and seeds of typical Euagaves 



Repeated personal observation of the plants in this region 

 which IS very rich in forms of Agave, has led to the belief 

 that there are but two separable species of this series one 

 ot them, A. rmcroacantha, comprising a number of what for 

 the present must be considered as hardly more than indi- 

 vidual variants, while the other, A. Karwinskii, seems more 

 constant in hs characters, except that in the southern part 

 ot Its range it becomes a veritable tree when fully developed 

 I have also had the satisfaction of seeing one of the old 

 Bessermna plants of the Missouri Botanical Garden flower 

 and fruit, corroborating conclusions based in the field on 

 foliage, bud, and fruiting material only. 



Though the leaf margin between the prickles is often quite 

 smooth, as was described for the original plants, it is fre- 

 quently granular-roughened in both species, especially in 

 the first-named,— locally if not throughout, and this character 

 IS shown by the Munich sheet of A. pugioniformis, the authen- 

 ticity of which appears reasonably certain. As with many 

 other Agaves, the margin on very young specimens is not 

 herbaceous m the sense of being gi-ecn, but is white and might 

 be called cartilaginous if it persisted on mature leaves as 

 It does more or less regularly in the related species of 'the 

 tequilam. alliance. 

 As forming a natural Euagave group, what may be called 



