ENGELMANN NOTES ON THE GENUS YUCCA. 49 



Var. ft. rigida: foliis pallidis glaucis planis doi'so carinatis 

 asperatis et capsulis cum seminibus minoribus. 



Western Texas in fertile soil mixed with broken up cretaceous 

 limestone rocks, discovered by F. Lindheimer, 1845, on the pla- 

 teaus west of New Braunfels, and described from his specimens 

 by Scheele : found afterwards by the botanists of the Mexican 

 Boundiry Survey; the second or southwestern form was sent by 

 Dr. Gregg from Mapimi in the Mexican State of Coahuila, and 

 by Dr Bigelow from the mountains of the volcanic district of 

 Bufatello near Presidio del Norte on the Rio Grande. — Flowers 

 in Texas in May and June, " after 2' Treculiana and before T. 

 angustifolia" 



As far as my information goes this species is always stemless : 

 a misapprehension of Lindheimer's notes must be the cause of 

 Scheele's, and after him Baker's, ranging it among the caulescent 

 Yuccas, with a " stem 4-7 feet high" ; rootstock of few stout 

 branches 1-2 feet long ; leaves dark or bright green, opaque, nar- 

 rowed above a not very broad base 1-2 feet long, f-if inches 

 wide with brown-red, strong serratures, mostly undulate, oblique, 

 one side longer than the other, therefore twisted, stout, thick, 

 sharp pointed, but not to be compared with T. aloifolia. Scape 

 4-7 feet high, with long leafy narrow lanceolate bracts ; panicle 

 with few large "greenish-white " flowers which apparently spread 

 3-4*, perhaps 5 inches, and are well characterized by the very acute 

 sometimes even aristate, when dried, strongly nerved, segments, 

 I i— 34 inches long, 10-14 lines wide, the inner wider than the 

 outer ; also by the erect or slightly spreading, never recurved 

 stamens, which are of the length of the prismatic ovary ; and by 

 the slender style, which, in all the specimens seen by me, is as 

 long as the ovary; ovules 0.2 mm. thick. Capsule 2-2* inches 

 long, about 1 inch thick, acute or cuspidate or rostrate, prismatic 

 or, very often, variously constricted or distorted, often showing 

 traces of the Yucca-moth ; secondary dissepiments sometimes 

 like those of most species, incomplete at top and bottom, but not 

 rarely, especially in very acute capsules, entire above or nearly so. 

 Seeds 7-8 mm. long, with a distinct but narrow margin. — This 

 form is reported to be in cultivation in France from Mr. Trecul's 

 seeds under the name of T. tortilis or contorta. 



Var. rigida looks very different indeed, with its smaller, pale, 

 yellowish or glaucous, often rough, straight leaves, only S-12 



iii— 4 [June 27, 1873.1 



