THE PINES OF MEXICO. 



23 



Pinus Montezumae var. Hartwegii Engelmann, Trdns. St. Louis Acad. Sci. iv, 177, 



181 (1880). 



Pinus Hartwegii Lindley, Bob Reg. xxv, Misc. 62 (1839). Loudon, Encycl. Trees & 



Shrubs, 1000, fig. 1875 (1842). Endlicher, Syn. Conif. 152 (1847). Parlatore, DC. 



Prodr. xvi, pt. 2, 399 (1868). Hemsley, Bot. Biol. Cent. Am. iii, 187 (1883). 



Pinus Donnell-Smithii Masters, Bot. Gas. xvi, 199 (1891). Smith, Bot. Gaz. xix, 13, t. 



2 (1894). 



Cones 6-12 cm. long, dull very dark brown or nearly black ; leaves 7-15 cm. in length, 

 often in fascicles of 3 or 4 as well as of 5 ; conelets blue or sooty black. 



Growing at cool temperate altitudes up to the tree limit. 



Nelson, 4 (398547) Salazar, Mexico; 177 (398548) no locality; 983 (398557) Yalalag, Oaxaca; 2534(398578) 

 Miahuatlan, Oaxaca: 3653 (,39 8 597) Chaucol, Guatemala; 6563 (398629) Mt. Patamban, Michoacan. Nelson 

 <Sn Goldman, 16 (396796) Volcan Iztacihuatl. Rose & Hay, 5780 (395567) Mt. Orizaba; 6076 (395881-2), 

 6325 (396144-5) Volcan Popocatepetl. Rose &> Fainter, 7953 (450779), 7971 (451591) Toluca, Mexico. 

 Maxon cV Hay, 3688 (473628), 3693 (474793) Volcan de Agua, Guatemala. Pringle, 8789, Ajusco, Mexico. 

 Shaw, Toro, Mexico. 



Both the varieties rudis and Hartwegii bear short, rigid, glaucous leaves, blue or blue-black conelets and com- 

 paratively small cones. The typical cones of var. rudis are brown in color, those of var. Hartwegii black. Var. 

 rudis grows at warmer temperate levels, var. Hartwegii in colder regions and at higher altitudes than any other 

 Mexican Pine. Leaves of var. rudis are in fascicles of 5, occasionally more, those of var. Hartwegii are often in 

 3's and 4's as well as 5's. The variety Hartwegii appears to be the variety rudis modified by exposure to severer 

 conditions. On the other hand the variety rudis may be considered a smaller form of the variety Lindleyi, sepa- 

 rated from it by its shorter leaves, smaller cones and blue conelets. The blue color of the conelet, however, is 

 superficial, for it disappears after a short immersion in alcohol. 



In Lambert's plate of P. Montezumae the cone is of the common subtropical form. Both cones 

 -and leaves often attain greater length than shown on the plate, but dimensions, in this species, are of no diag- 

 nostic value. Three cones taken from a single tree at Cuernavaca measure 12, 15 and 20 cm. The 

 type passes into the variety Lindleyi through numerous intermediates, which may be found in great numbers 

 in the states of Tlaxcala, Puebla and Vera Cruz, directly east of the City of Mexico. 



Trees bearing fascicles of 6, 7 or 8 leaves are quite common, but such excessive numbers are found usually 

 on older trees and in favorable years. On young trees fascicles of 3 and 4 leaves may be found, but in all 

 cases fascicles of 5 predominate. The epiderm of the bsanchlets falls away sooner or later, but the cushions 

 formed by the decurrent bases of the bracts remain, their freshly exposed surfaces being of a buff gray color. 

 This character is common to all forms of P. Montezumae and may be seen on several of the specimens of the 

 Nelson collection; it also appears on cultivated specimens sent to me from southern England. 



PLATE XVI. 



Fig. 1, 2. Cones of var. rudis. Fig. 6. Cone of var. Hartwegii. 



" 3. Leaf-section of Nelson 4567, magn. 30 diam. " 7. Leaf-section of " magn. 30 diam. 



" 4. " " " " 4916, " " " " 8. Habit of var. rudis. 

 " 5. Conelet of Nelson 4916. 



