39. PINUS PONDEROSA
- 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.
Like P. Montezumae, and under like influences, it shows much dimensional variation, and the leaf-fascicles are heteromerous, with the larger number in the southern part of its range. Many authors consider the variety Jeffreyi Vasey to be a distinct species; but here, it seems to me, too much importance is attached to the pruinose branchlet, clearly a provision against transpiration and associated rather with a dry environment than with a species. Most observers discover many intermediate forms between this variety and the species. The var. scopulorum Engelm. is the Rocky Mountain form with leaves in 2's and 3's and with small cones passing into P. arizonica, Engelm., a more southern form with small cones and leaves in fascicles of 3 to 5. The var. macrophylla (Shaw, Pines Mex. 24), in addition to its long and stout leaves, bears a cone with protuberant apophyses, somewhat comparable to the intermediate forms of P. pseudostrobus var. apulcensis Shaw (l. c.). Fascicles of 6 and 7 leaves are sometimes found, and specimens that I have collected in Sandia, Durango (issued by Pringle, through a misunderstanding, under the name P. Roseana, ined.) show such fascicles on the fertile branches.
Fig. 230, Cone and seed of var. Jeffreyi. Fig. 231, Cone of var. macrophylla. Fig. 232, Cone of var. scopulorum. Fig. 233, Magnified leaf-section and cells of leaf-endoderm. Fig. 234, Magnified dermal tissues of the leaf, showing uniform and multiform hypoderm.