THE YUCCEAE.* 

 C? 



BY WILLIAM TKELKASE. 



INTRODUCTION. 



H 



The large family Liliaceae has been subjected to very 

 different treatment by the writers who at various times 

 have monographed it or attempted to indicate a natural 



> sequence for its genera. The tribes Aloineae and Yuccoi- 

 deae, respectively African and American, were treated to- 



-4 gether by Mr. Baker f with the implied recognition of 



^ close affinity, the principal synoptic differences between 

 them consisting in the succulent leaves and gamophyllous 

 perianth of the former, and the less succulent more fibrous 

 leaves and distinct perianth segments of the latter, in 

 which he includes Yucca, Hesperaloe, Herreria, Beau- 

 carnea, and Dasylirion.\ 



Bentham and Hooker also place the aloids and yuccoids 



^ close together, characterizing the tribe Dracaeneae, in 

 which the latter are included, by its mostly distinct perianth 



V segments, U and including in it Hesperocallis, Hesperaloe, 

 Yucca, Nolina (Beaucarnea), and Dasylirion, of the New 



* Presented in abstract, with lantern illustrations, before the Botan- 

 ical Society of America, at its New York meeting, June 28, 1900, and 

 before the Academy of Science of St. Louis, Feb. 3, 1902. 



t Journ. Linn. Soc. Bot. 18: 148. (1881). 



J 1. c. 152. 



Genera Plantarum. 3: 750, 777. (1883). 



t The generic descriptions show that the segments are connate into 

 a tube in Hesperocallis , Dracaena, Cordyline, Milligania, and some species 

 of Astelia, and barely united at the base in Yucca. 1. c. 778. 



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