1S92.] l-O [neilprin. 



Tlie extended vertical distribution of llie pines is very remarlvable, not 

 less so than the abrupt limitation southwards of the genus. If the identi- 

 fication of the common form of Britisli Honduras and of Cuba {Finns 

 Cubensis) with P. Montezuma (P. occidentalis) be considered correct — for 

 which, however, there appears to be considerable doubt — and similarly, 

 the identification ot this last with the species (or one of the species) grow- 

 ing in the upper vegetal zone of Orizaba, etc., then the range of a single 

 species is made coincident with that of the entire genus — indeed, so far as 

 the western hemisphere is concerned, with that of the entire family or 

 tribe. Nor is there, probably, another instance known of a perennial 

 having an equivalent range of 14,000 feet, or upwards of two and a half 

 miles.* Humboldt places the lower limit of P. Montezumm in Mexico 

 at 4093 feet (at very nearly the position in which I found it below Buena 

 Vista on the road connecting Ario de Rosales with the hacienda of La 

 Playa, base of Jorullo), and its upper limit, as determined by him on the 

 Cofre di Perote, at 13,936 feet.f Liebmann places the upper limit, on the 

 northwestern side of the Peak of Orizaba, still higher, or at about 14,000 

 feet. J I am not certain that we observed, whether on Orizaba, Popo- 

 catepetl, or Ixtaccihuatl, the common "long-leaved Mexican pine" at 

 anything like this elevation ; certain it is that while this species enters, 

 with the P. Teocote and P. pseudostrobus, very largely into the formation 

 of the lower pine woods of the mountains in question, at elevations of from 

 9000 to 11,000 feet or thereabouts, it is distinctly succeeded in the upper 

 zone by the very common short-leaved form (Pinus Ayacahuitc) and P. 

 Hartwegii. That these various forms have been repeatedly interchanged 

 by botanists and travelers is positive ; nor, indeed, in the present 

 uncertainty regarding the species of Mexican pines, would it be safe to 

 assert that all these species are really distinct. We also found the upper 

 limit of the pines on Orizaba to be close on the 14,000-foot line, but on the 

 adjacent Sierra Negra, which faces the peak of Orizaba on the south, 

 the tree line appears to rise fully two or three hundred feet higher. 

 As Liebmann observes, the trees become in a measure dwarfed, though 

 never shrubby or prostrate. At an elevation of 13,300 feet, where they 



limestone mountains west of Yautepec (on the ridge separating thiat town from Cuerua- 

 vaca), at an altitude of 6500 feet ; the same species appears still higher, 7000-7500 feet, on 

 the similar calcareous soil of the region about (uorth of) Tehuacan. At both localities the 

 palm, together with the Viznaga ( Viznaga mammiUaris) , and the organ cactus, forms the 

 predominant feature of the vegetation ; the stem rises to some 30-35 feet. Liebmann 

 states that Corypha and Chamserops are both found on the highlands of Mexico at au 

 elevation of 8000 feet. Hemsley is probably correct in referring one of these forms to 

 Brahea ; the other may be a Chamsedorea, but it seems to me more likely to be a true 

 Sabal. Drude has, perhaps, doubted the accuracy of Liebmann's observations, since he 

 makes no mention of any Mexican palm rising above 5000 feet ("Die Geographische 

 Verbreitung der Palmen," in " Petermaun's Mittheilungen," 1S78: " Handbuch der 

 Pflauzengeographie," 1890). 



*The Oregon pine or Douglas fir {Pseudotsuga Douglasii) extends its habitat from the 

 sea level on the Pacific coast to an elevation of nearly 10.000 feet in Colorado. 



t" Views of Nature," Bohn's edition, p. 315. 



X If French feet, then more nearly 15,000 feet. 



