CONIFERS. 



8ILVA OF NORTH AMERICA. 



91 



usually seventy or eighty but often one hundred and fifty feet in height, with a trunk generally 

 from two to three but occasionally five or six feet in diameter, and slender much forked branches 

 frequently persistent nearly to the base of the stem, which are light orange-color during their early 

 years and somewhat pendulous below, and ascending near the top of the tree form a narrow pyramidal 

 spire-topped head. In the extreme form the bark of the trunk is rarely more than a quarter of an inch 

 in thickness, close and firm, light orange-brown, and covered by small thin loosely appressed scales. 

 The leaves are yellow-green and usually about two inches long, although they vary from one to three 

 inches in length, and are from one sixteenth to nearly one eighth of an inch in width. The cones 

 occasionally open as soon as ripe but are usually serotinous, preserving the vitality of their seeds 

 sometimes for twenty years. 1 



Beissner, Handb. Nadelh. 219. — Masters, Jour. R. Hart. Soc. xiv. 

 227. — Koehne, Deutsche Dendr. 37. 



Pinus inops, Bentham, PL Hartweg. 337 (not Aiton) (1857). 

 Pinus Murrayana, A. Murray, Rep. Oregon Exped. 2, t. 3, 62 

 (1853) ; Edinburgh New Phil. Jour. n. ser. xi. 226 ; Trans. Bot. 

 Soc. Edinburgh, vi. 351. — Sargent, Forest Trees N. Am. 1(M 

 Census U. S. ix. 194. — Lemmon, Rep. California State Board 

 Forestry, ii. 72, 92, t. (Pines of the Pacific Slope) ; West- American 

 Cone-Bearers, 30, t. 4. — Steele, Proc. A m. Pharm. Assoc. 1889, 

 236 (The Pines of California). — Mayr, Wald. Nordam. 348, t. 

 8, f. — Hansen, Jour. R. Hort. Soc. xiv. 378 (Pinetum Dani- 

 cum). — Merriam, North American Fauna, No. 7, 339 (Death 

 Valley Exped. ii.). 



Pinus contorta, Newberry, Pacific R. R. Rep. vi. pt. iii. 34, 90, 

 t. 5, f. 11 (not Loudon) (1857). — Engelmann, Am. Jour. Sci. 

 ser. 2, xxxiv. 332. — Lyall, Jour. Linn. Soc. vii. 141 (in part). — 

 Cooper, Am. Nat. iii. 409. — Parlatore, De Candolle Prodr. xvi. 

 pt. ii. 381 (in part). — Masters, Gard. Chron. n. ser. xix. 45, f. 5. 

 Pinus Tamrac, A. Murray, Gard. Chron. 1869, 191, f. 1-9. 

 Pinus contorta, var. latifolia, Watson, King's Rep. v. 331 

 (1871). — Porter & Coulter, Fl. Colorado ; Hoyden's Surv. Misc. 

 Pub. No. 4, 129. — Engelmann, Rothrock Wheeler's Rep. vi. 262. 



Pinus Murrayana, var. Sargentii, Mayr, I. c. 349 (1890). 

 It would probably be hopeless to try to convince a person who had 

 seen these trees only on the high California Sierras, in the Yellow- 

 stone National Park, and on the sand dunes of the Pacific coast, 

 that Pinus Murrayana and Pinus contorta were forms of one species, 

 although they do not differ in their organs of reproduction except 

 in the size of the cones, which varies considerably on different 

 individuals. The extreme forms vary in their habit, in the thick- 

 ness, color, and nature of their bark, in the character of their 

 wood, in the length and breadth of their leaves, and in the size of 

 their cones ; one is a tall pyramidal tree of high mountains and 

 plateaus with orange-colored bark thinner than that of any other 

 Pine and soft straight-grained wood with inconspicuous summer 

 cells and more like that of a White Pine or of a Spruce than of a 

 Pinaster, and with broad yellow-green leaves ; the other is a low 

 round-headed coast tree with stout contorted branches, thick dark 

 deeply furrowed bark, coarse-grained wood conspicuously marked 

 by broad dark bands of resinous summer cells, and slender dark 

 oreen leaves. In the region, however, between the coast and the 

 northern Rocky Mountains there are other forms, some with broad 

 and others with narrow leaves, some with bark as rough as that of 

 the coast tree, and others with the thin bark of the mountain tree ; 

 on some trees dark thick bark occurs only at the base of the trunk, 

 on others it extends several feet above it and gradually passes into 

 the thin orange-colored bark of the mountain tree. The wood, too, 

 of the trees of the Olympic and Cascade Mountains, of the ranges 



of western Washington and Oregon, and of northern Idaho and 

 Montana, varies like the bark, and individuals may be found grow- 

 ing under apparently identical conditions with the pale soft wood 

 of one form and with the dark resinous wood of the other ; and 

 after wandering for months among these trees and seeing them in 

 all their aspects, on the Yellowstone plateau, in northern Montana 

 and Idaho, on the Blue Mountains of eastern Oregon, on the Cas- 

 cades and the Olympics, along the coast from the shores of the 

 Straits of Fuca to those of Humboldt Bay, on the borders of alpine 

 meadows and the moraines of the Sierra Nevada, and on the moun- 

 tains of Colorado, the conclusion forced itself upon me that a single 

 species, greatly changed in some respects by its surroundings in 

 different localities, but always with the same organs of reproduc- 

 tion, extends over this wide region. 



1 In 1874 Dr. George Engelmann gathered on the Rocky Moun- 

 tains of Colorado a branch of Pinus contorta, var. Murrayana, bear- 

 ing closed cones, which had ripened during each of the previous 

 nine years, with the exception of 1867, when none had been pro- 

 duced. In the spring of 1879 seeds from the cones of each year 

 were planted at the Arnold Arboretum. Those from the cones 

 which had ripened in 1866 did not germinate, but a part of the 

 seeds of later years produced seedlings, showing that the seeds of 

 this tree may preserve their vitality in closed cones for as long a, 

 period as nine years, although under ordinary conditions Pine seeds 

 are extremely perishable. (See Sargent, Bot. Gazette, v. 54. — 

 Engelmann, Bot. Gazette, v. 62.) 



This special arrangement for protecting the vitality of its seeds, 

 and their power to germinate quickly on burnt soil after liberation, 

 have enabled Pinus contorta to maintain itself against adverse con- 

 ditions and to play a controlling part in determining the character 

 of the forests over large areas in the northern Rocky Mountain 

 region. Fires are constantly sweeping through these forests, kill- 

 ing, without consuming, these highly resinous trees, of which they 

 are now at certain altitudes often almost exclusively composed. 

 The heat opens the cones and liberates the seeds of many years, 

 and these, falling in immense numbers on the burnt surface of the 

 ground, germinate quickly, and, growing rapidly, soon cover it to 

 the exclusion of other plants, forming such dense forests that a 

 man can hardly find passage between the slender stems of its trees. 

 These trees begin to bear cones profusely when only a few years 

 old, and are soon ready to furnish seeds to repair the damage of 

 another fire. This alternate burning of older trees and springing 

 up of crops of seedlings on the same ground may go on for genera- 

 tions ; and it is common to see on the Rocky Mountains the dead 

 trunks of three or four crops standing over a dense young growth. 

 In this way the Lodge Pole Pine is not only able to hold its own on 

 ground of which it has once taken possession, but also to gain and 

 maintain a foothold where fire has destroved other trees less well 



