THE YUCCEAE. 117 



The species may be differentiated as follows : 



Perianth-tube conical, under 10 mm. long. g. Faxoniana. 



Perianth-tube 12 to 25 mm. long. g. Carnerosana. 



S. Faxoniana Trelease. 



Yucca australis Trelease, Kept. Mo. Bot. Gard. 4 : 190. pL 4, 5. 



Coulter, Contr. U. S. Natl. Mus. 2 : 436, in part. 

 r. macrocarpa Sargent, Gard. & Forest. 8 : 301, 305. /. 42. 9 : 104. - 



Silva. 10 : 13. pi. 499. 



Arboreous, 1.5 to 5 m. high, .3 to .6 m. thick, simple or few branched 

 at top. Leaves 50 to 75 mm. wide, 1 to 1.25 m. long, openly concave to 

 the end, shagreen-scabrid only on the dorsal angles if at all, coarsely 

 flliferous but at length with only a few persistent short pectinate threads 

 near the apex and a cobwebby mass of detached fibers at base. Panicle 

 short stalked, broadly pyramidal, rather loosely branched, with very large 

 persistent at length brittle white bracts. Flowers expanding 50 to 100 mm., 

 white; perianth tube scant 10 mm. long. Fruit oblong-ovoid, 25 to 76 

 mm. long and 25 mm. in diameter. Plates 69-71. 78, f. 2. 81,f. 11. 



About Sierra Blanca, Texas, and presumably extending 

 southwards into Mexico. Plate 94, f. 2. 



Travelers who pass Sierra Blanca, in western Texas, by 

 daylight, are usually interested in the scattering forest of 

 low Ywcca-like trees covering the surrounding country, a 

 number of which are planted about the section-house and 

 in what was formerly a very attractive collection of succu- 

 lents at the railroad station. 



In the absence of type material or any collections from 

 the type localities, these trees have been considered to 

 represent 'the Yucca baccata macrocarpa of Torrey, and, 

 under the name Y. macrocarpa or its partial synonym 

 Y> australis, are described and figured in several places. 

 Associated with them are numerous specimens of Y. radiosa 

 and, in smaller numbers, the true Y. macrocarpa of the 

 great bend of the Rio Grande, which, as has been shown 

 above, is a well-marked species and preserves all of the 

 floral characters of a true Yucca; and, as indicative of their 

 probable range to the southward, it may be mentioned that 

 they are accompanied by Agave applanata, which, in its 

 typical form, is not known elsewhere in the United States. 



