ROSE MEXICAN AND CENTRAL AMERICAN PLANTS. ^7 



LILIACEAE. 

 DASYLIRION AND ITS ALLIES. 



After passing in review the specimens and descriptions of I >asylirion 

 and Nolina I have become convinced that certain species should be 

 excluded from both and brought together Into a third genus. Some 

 of these species have long been known as Beaucarhea and arc an 

 attractive sight in every large conservatory. 



The v discovery of female flowers and mature fruit- of the so-called 

 Dasylirion hookeri furnishes data which justify it- segregation also. 



The following key will point out the essential differences in these 

 genera: 



Ovary L-celled; fruit strongly 3-winged. 



stems Btrongly bulbose at base; leave- never saw-toothed; in- 

 florescence a broad open panicle Be u « irnea. 



Stems never bulbose at base; leaves saw-toothed 'except in one 



species); inflorescence an elongated spike-like panicle Dasylibion. 



Ovary 3-celled; fruit not at all winged. 



Fruit not 3-lobed, its walls very thick and woody, n<>t dropping 



away; trunk a swollen globular body ( ' u.ikani -. 



Fruit Btrongly 3-lobed, its wall very thin, soon dropping away: 

 trunk if present never -w ollen Nolina. 



BEAUCARNEA. 



The genus Beaucarnea was described by Lemaire in L861 with B. 

 recur-vata as the type. Two other species (B. striata and B. gracilis) 

 were also described by him. In ls~'2 and also in L881 J. (i. Baker 

 monographed the genus, combining with it the much older genus 

 Nblina. lie describes twelve species and several varieties. In 1^7.~> 

 S. Watson monographed the United State- species of Nblina, stating 

 that the Mexican species of Beaucarnea described by Mr. linker should 

 doubtles- be referred to Nolina. Three years after Mr. Baker's !;;-t 

 paper Mr. Hemsley again takes up the name Nolina. and -<> the two 

 names have been alternating, firsl one and then the other receiving the 

 sanction of botanists. In America the name Nolina. being much the 

 older, ha- generally been accepted by botanists, while gardeners 

 throughout the world have, asa rule, clung to Beaucarnea. 



After a careful study of the species alone' with those ^\' Dasylirion 

 it seems clear that both genera should be retained. For at least two 

 accepted species of Dasylirion with several referred to Beaucarnea 

 and Nolina form a very natural genus abundantly distinct from both 

 Nolina and Dasylirion. The genus Beaucarnea ha- the inflorescence 

 and foliage similar to those of Nolina while the fruit is much like 

 that of Dasylirion: hence heretofore those species of Beaucarnea 



" Be \n .\i;\i: \ Lemaire, Illu-t. Hortic. 8: Misc. : >7. pi. SOS. 1861. Typeepecies B 

 recurvata. 



4153— vol x. pt 3—06 '2 



