THE YUCCEAE. 69 



parently the same thing at Monclova, in the State of Coa- 

 huila. To these latter, Dr. Engelmann attached the manu- 

 script name Y. rostrata, descriptive of the long-attenuate 

 apex of the fruit. 



While passing between Eagle Pass and Monterey, in 

 company with Professor Sargent and Mr. Canby, in March 

 1900, my attention was attracted by a narrow-leaved 

 Yucca that was cultivated at C. P. Diaz and in station 

 yards along the Mexican International railroad, and that 

 was found forming a natural low forest about Peyotes, on 

 the water-shed between the Rio Grande and Sabinas, where, 

 on subsequent visits, in April and August, I was able to 

 study it in detail. 



Among Yuccas this is conspicuously loosely rooted in the 

 soil, so that large plants are easily removed. The trunks 

 vary in height from about .3 m. to an observed maximum 

 of about 3m., the usual height being about 2m., and the 

 wood is extremely soft and spongy. When the old 

 leaves are removed, the diameter of the stem is usually .15 

 or .2 m., and it is not dilated except where the roots start 

 from the base. Older plants are sometimes branched at the 

 top, but the branches remain short, so that these trees 

 usually possess several subapical crowns of leaves, rather 

 than a series of separated elongated branches, like those 

 of many other arborescent species. 



The leaves are very numerous, radiating in every direc- 

 tion from the top of the stem in an oblong or usually nearly 

 globose crown some 1.25 to 2 m. in diameter, and, although 

 thin, they are sufficiently rigid rarely to become arched from 

 their own weight, as they are in the species of N^olina, like 

 JW. longi folia, with similar foliage. They are flattened or a 

 little biconvex, quickly contracted from a broad base and then 

 very narrowly lanceolate, measuring about 6 mm. at the nar- 

 rowest point and 12 mm. at the widest, which is about one- 

 third their length below the grooved, acute, pungent apex. 

 They are somewhat glaucous, occasionally slightly twisted 



