98 MISSOURI BOTANICAL GAEDEN. 



Y. SCHOTTII Engelmann, Trans. Acad. St. Louis. 3:46, 

 (1873). Watson, Proc. Amer. Acad. 14:252. 

 Baker, Journ. Linn. Soc. Bot. 18:228. Trelease, 

 Kept. Mo. Bot. Gard. 4:185. pi. 3. Sargent, Silva. 

 10:17. pi. 501. In part. 



Y. macrocarpa Engelmann, Bot. Gazette. 6:224. (1881). 7:17. 

 Baker, Kew Bull. 1892 : 8. Trelease, Kept. Mo. Bot. Gard. 3 : 162. 

 pi. 46. 

 ? Y. Mazeli Chabaud, Belg. Hort. 1882 : 222. Wiener 111. Garten- 



Zeit. 11 : 347. Baker, Kew Bull. 1892 : 8. 



Arborescent, rarely over 3 or 4 m. high, simple or few branched above. 

 Leaves blue-green, smooth, rather rigidly divergent, thin, concave, pun- 

 gent, 20 to 40 mm. wide, very finely and often sparingly filiferous. In- 

 florescence densely panicled close to the leaves, very tomentose or rarely 

 nearly glabrous. Flowers subglobose. Fruit oblong, mostly large: 

 seeds 7 X 9 mm - Plates 55. 85, f. 1 . 



Southern Arizona, especially about Benson and Nogales, 

 and as far into the Mexican state of Chihuahua at least as 

 Colonia Garcia. Flowering in late summer. Plate 96, 



f-i- 



When, in 1882, Dr. Engelmann described fuller material 

 of the Arizona Yucca which he had named Y. macrocarpa 

 the year before, he was so impressed with the resem- 

 blance of its tomentose panicle to the fragments of inflo- 

 rescence in the Torrey herbarium accompanying the leaves 

 of what he had called Y. 8chottii, that he suggested that 

 the latter might possibly be only a short-leaved form of 

 the same species. This suggestion has been adopted by a 

 number of recent writers, who, irrespective of a prior use 

 of the name macrocarpa in the genus, have come to look 

 upon Y. macrocarpa Engelm. as a synonym of Y. Schottii. 



This Y. Schottii of recent writers is abundant to the west 

 and northwest of Nogales, as far, at any rate, as the vicin- 

 ity of Benson and the Pajarito mountains, and there be- 

 comes a small tree two or three meters high, most frequently 

 unbranched ; and it is especially marked among the Yuccas 

 of the region by the bluish-green color and thinness of its 

 smooth concave finely filiferous brown-margined leaves, and 



