1836 P. ponderosa Douglas ex Lawson's Agric. Man. 354. 1847 P. Benthamiana Hartweg in Jour. Hort. Soc. Lond. ii. 189. 1848 P. brachyptera Engelmann in Wislizenus, Tour Mex. 89. 1848 P. macrophylla Engelmann in Wislizenus, Tour Mex. 103 (not Lindley). 1853 P. Jeffreyi Balfour in Bot. Exp. Oregon, 2, f. 1854 P. Engelmanni Carrière in Rev. Hort. 227. 1855 P. Beardsleyi Murray in Edinb. Phil. Jour. ser. 2, i. 286, t. 6. 1855 P. Craigana Murray in Edinb. Phil. Jour. ser. 2, i. 288, t. 7. 1858 P. Parryana Gordon, Pinet. 202 (not Engelmann). 1859 P. deflexa Torrey in Emory's Rep. ii. 1, 209, t. 56. 1878 P. arizonica Engelmann in Wheeler's Rep. vi. 260. 1889 P. latifolia Sargent in Gar. & For. ii. 496, f. 135. 1894 P. apacheca Lemmon in Erythea, ii. 103, t. 3. 1897 P. Mayriana Sudworth in Bull. 14, U. S. Dept. Agric. 21. 1897 P. scopulorum Lemmon in Gar. & For. x. 183. 1900 P. peninsularis Lemmon, W. Am. Conebear. 114. Spring-shoots uninodal, sometimes pruinose. Bark-formation early. Leaves prevalently in fascicles of 3, but varying from 2 to 5 or more, from 12 to 36 cm. long; resin-ducts medial, hypoderm uniform or multiform, outer walls of the endoderm thick. Conelet mucronate, the mucro often reflexed. Cones from 8 to 20 cm. long, ovate-conic, symmetrical, deciduous and usually leaving a few basal scales on the tree; apophyses tawny yellow to fuscous brown, lustrous, elevated along a transverse keel, sometimes protuberant and reflexed, the umbo salient and forming the base of a pungent, persistent prickle. This species ranges from southern British Columbia over the mountains between the Pacific and the eastern foot-hills of the Rocky Mountains, including the Black Hills of South Dakota, to the northeastern Sierras of Mexico, to northern Jalisco and Lower California, forming, in many localities, large forests and furnishing the best Hard Pine timber of the western United States. It attains its best growth on the Sierras of California and is, next to P. Lambertiana, the tallest of the Pines.