THE DESERT GROUP NOLINE^. 

 (Plates I-XVII.) 



By WILLIAM TRELEASE. 

 (Read April 21, 1911.) 



History. 



The four genera NoUim ( Michaiix, 1803), Dasylirion (Zucca- 

 rini, 1838), Bcaucarnca (Lemaire, 1861 ) and CaUbanns (Rose, 1906) 

 form so natural a group that many botanists have considered a 

 single generic name, Dasylirion, suf^cient for all, though they differ 

 enough in fruit to have caused the founder of this genus to question 

 the propriety of including in it all of the species that were known 

 even in his day ; and they show marked differences in habit. 



Except that Dasylirion was based in part on a Hcchtia, which 

 led its author — who later recognized the error — to place it among 

 the Bromeliacese. and that on his suggestion it has been connected 

 transiently with the Juncace?e, this genus and its immediate rela- 

 tives have been accorded place generally among what are now con- 

 sidered as Liliaceffi, — though not always under that family when its 

 rather heterogeneous components have suft'ered temporary segrega- 

 tion. Xo better arrangement has been found than that of Engler 

 and Prantl'^ who locate the Nolinese between Yuccese and Dra- 

 cseneas as part of the Draceanoid Liliace^e. From the Yuccese they 

 are sharply differentiated, among other characters, by their small 

 polygamo-dioecious flowers (never 10 mm. in diameter), few- 

 ovuled pistil, and small usually indehiscent fruit rarely more than 

 one-seeded : and the Dracaenese differ from them in a usually some- 

 what gamophyllous perianth, perfect flowers, and prevailingly 

 fleshy fruit, — but in all of these respects the group of Dracasneae 

 offers a good deal of latitude. 



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