THE YUCCEAE. 53 



and partly because of generalized earlier descriptions. One 

 of the representatives of this group (probably true Y. fila- 

 mentosa) was introduced into Europe about 1675, and 

 Y. filamentosa was one of the four Yuccas known to Lin- 

 naeus a century later, his description of it reading merely 

 "foliis serrato-filamentosis," and the only figure cited by 

 him * being very unsatisfactory. 



That two species, Y. filamentosa and Y. flaccida, are 

 separable, appears certain, as is also true of Engelmann's 

 conclusion f that the filamentosa of Linnaeus was th 

 form to which that name is here applied ; but I have found 

 it possible to fix only an approximate geographical range 

 for either, and the garden forms are not separated as 

 sharply as is desirable, nor so as to prevent some of them 

 from obscuring the demarcation line between the species. 

 It is not improbable that some of them represent hybrids 

 between the latter. 



44. Leaves linear or linear-spatulate, white-margined. 



Y. tciiuistyla Trelease. 



Acaulescent. Leaves rather soft and mostly recurving, often a little 

 scabrid on the back, about .5 m. long and 10 to 15 mm. wide, dark green, 

 lanceolate, long-attenuate, scarcely pungent, white-margined, finely 

 flliferous. Inflorescence about 1 m. high, panicled at some distance above 

 the leaves, glabrous or slightly puberulent. Flowers with narrower, 

 more pointed segments : style oblong, white, often deeply parted. Capsule 

 stout, even : seeds glossy, 7 to 8 X 8 to 10 mm. Plates 17,f. 2. 18. 19. 

 83>f.S. 



Southeastern Texas, from about Galveston (Lindheimer, 

 May, 1843), to Sealy (Trelease, Harvey), and New 

 Braunfels (Lindheimer, June, 1845), at the latter place 

 associated with Y. Arkansana, which it closely resembles 

 in foliage. Plate 92, f. 1. 



Some of the Lindheimer material in the Engelmann her- 



* Morison, Plant. Hist. 2 : 419. 

 t Trans. Acad. St. Louis. 3 : 52. 



