THE PINES OK MEXICO. 



DISTRIBUTION 



The northern and central States of Mexico from a vast, arid, elevated table-land bordered by 

 high mountains sloping abruptly to the coasts on the east and west and, on the south, into a 

 country broken by mountains and valleys of various altitudes. 



Only the lowlands of the coast and southern States up to altitudes of 1000 metres 

 above the sea are tropical. On the slopes and table-lands between looo and 2000 metres the 

 climate is subtropical. At 2000 to 3000 metres the climate is temperate with warm days and 

 cool nights; this zone includes the general level of the great table-land and the slopes im- 

 mediately above it. On the mountains above this table-land the average temperature de- 

 creases until, at the highest altitudes, the climate is boreal. 



The vertical range of the Pines in Mexico is approximately between 1200 and 4500 metres 

 above sea level. Each zone is represented by charactristic species. P. Pringlei, P. Lawsoni, 

 and P. oocarpa are confined to subtropical regions ; P. teocote, P. patula, P. Grcggii, P. Lum- 

 holtzii and P. ayacahuite grow in temperate altitudes as well as the Nut- Pines, P. cembroides, 

 P. Pinceana and P. Nelsoni which are found on the dry slopes just above the great table-land. 

 Of the other Mexican species, P. pseudostrobus and P. leiophylla grow at both subtropical 

 and temperate altitudes, while P. Montezumae is met at all levels except the tropical. The typical 

 and most luxuriant form of this species is subtropical, while its hardiest form (var. Hartwegii) in- 

 habits the highest altitudes where, at the timber line and for some distance below, it is the only 

 Pine. 



Northern Mexico has been invaded by a few species properly belonging to a more northern 

 flora. P. contorta and P. Lambertiana occur in a single locality of northern California Baja, 

 while P. ponderosa and P. flexilis grow as far south as the 23rd or 24th parallel of north 

 latitude. 



In Mexico no tropical Pine has yet been found, but in Honduras and eastern Guatemala the so-called Cuban 

 Pine P. caribaea Morelet, indigenous also in Florida and the Bahamas, is abundant. The Mediterranean Pine, P. 

 halepensis Miller is planted to a limited extent in the public parks of the large cities. P. Pinea L. is also said 

 to be cultivated in Mexico but I have not seen it there. 



Mexican Pines have not generally succeeded in cultivation. The species that are exclusively subtropical 

 are too tender for southern England or northern Italy, but in the Botanical Garden at Buitenzorg, Java, the 

 subtropical form of P. Montezumae has borne perfect fruit for many years. Of the temperate Pines the hardier 

 forms of P. Montezumae have been grown under Lindley's names in the gardens about Lake Maggiore in northern 

 Italy and in Devonshire and Cornwall in England. P. ayacahuite var. Veitchii seems perfectly hardy at 

 Pallanza, Italy, and at Westonbirt, Gloucestershire. P. patula succeeds at Pallanza, at Bicton, Devonshire and 

 at Fota, southern Ireland. From Bicton and Fota I have received branches and leaves of P. Teocote but no 

 fruit. Considering the amount of seed distributed by Roezl and by Hartweg the results obtained are not 

 encouraging except in regions of exceptionally mild climate. 



MAP 



In order to present a clear idea of the territory covered by the collections examined, the cities and towns 

 mentioned in the text are approximately located on the map opposite. 



The "Federal District" and the "Valley of Mexico" are limited areas within the State of Mexico; where these 

 names occur on the collectors' labels they are changed to "Mexico" in the text. 



