coNiFEEiE. SILVA OF NORTH AMERICA. 39 



PINUS ALBICAULIS. 



White Pine. 



Leaves in 5-leaved clusters, thick, rigid, from \\ to 2J inches in length. Cones 

 oval or subglobose, from \\ to 3J inches long, their scales much thickened, dark 

 purple, terminating in stout incurved nearly triangular tips. 



Pinus albicaulis, Engelmann, Trans. St. Louis Acad. ii. R. Hort. Soc. xiv. 345 (Pinetum Danicum). — Koehne, 



209 (1863) ; Linncea, xxxiii. 390 ; Bot. Gazette, vii. 4. — Detitsche Dendr. 31. 



Hall, Bot. Gazette, ii. 94. — Lawson, Pinetum Brit. i. Pinus flexilis, A. Murray, Rep. Oregon Exped. 1, t. 2, f. 1 

 1, f. 1-4. — Sargent, Forest Trees N. Am. 10th Census (not James) (1853). — Lyall, Jour. Linn. Soc. vii. 142.— 



U. S. ix. 189. — Hooker f. Gard. Chron. n. ser. xxiv. 9, Parlatore, Be Oandolle Prodr. xvi. pt. ii. 403 (in part). 



f . 1, 2. — Lemmon, Rep. California State Board Forestry/, Pinus cembroides, Newberry, Pacific R. R. Rep. vi. pt. 

 ii. 70, 84, t. (Pines of the Pacific Slope) ; West-American iii. 44, 90, f. 15 (not Zuccarini) (1857). 



Cone-Bearers, 24. — Steele, Proc. Am. Pharm. Assoc. Pinus Shasta, Carriere, Traite Conif. ed. 2, 390 (1867). 



1889, 234 (The Pines of California). — Mayr, Wold. Pinus flexilis, var. albicaulis, Engelmann, Brewer & 

 Nordam. 354, t. 7, f. — Beissner, Handb. Nadelh. 27 4.— Watson Bot. Cat. ii. 124 (1880). — Coulter, Man. 



Masters, Jour. R. Hort. Soc. xiv. 225. — Hansen, Jour. Rocky Mt. Bot. 432. 



A tree, twenty or thirty or rarely sixty feet in height, with a short or rarely elongated trunk from two 

 to four feet in diameter, or often at high altitudes a low shrub with wide-spreading stems. During its 

 early years the stout branches, which are so flexible that they may be tied into knots, are arranged in 

 regular whorls and stand out from the stem at right angles, forming a narrow compact pyramid ; * later, 

 several of the specialized upper branches grow much more rapidly than the others or than those below 

 them, and, turning upward, stand at acute angles with the stem, forming an open very irregular compar- 

 atively broad head. The bark at the base of old trunks is sometimes half an inch in thickness, although 

 on the body of the stem, on young trees, and on the large branches it is usually not more than from one 

 eighth to one quarter of an inch thick, and is broken by narrow fissures into thin light brown or 

 creamy white plate-like scales which when they fall disclose the light reddish brown inner bark. The 

 branchlets are stout, puberulous sometimes during two years, or glabrous before their first winter, dark 

 reddish brown or rather bright orange-color, and after they shed their leaves much roughened by the 

 prominent scars left by the falling of the bud-scales. The winter branch-buds are broadly ovate, 

 acute, and covered by loosely imbricated pale chestnut-brown scales, the terminal bud being often half 

 an inch long and from one third to nearly one half of an inch wide, and much larger than the lateral 

 buds. The leaves are arranged in clusters of five, with deciduous pale chestnut-brown sheaths about 

 half an inch in length, the inner bud-scales being oblong-obovate and rather prominently ribbed, and 

 are borne in dense tufts at the ends of naked branches ; they are slightly incurved, stout and rigid, 

 with a thick-walled epidermis, and are marked with from one to three rows of dorsal stomata ; they are 

 dark green, acute, and entire on the margins, and usually about an inch and a half in length, although 

 on trees in sheltered positions sometimes nearly three inches long, and contain a single fibro-vascular 

 bundle and two dorsal and sometimes also a ventral resin passage surrounded by strengthening cells ; 2 

 the leaves on some trees begin to fall in their fifth season and drop irregularly, many of them remaining 

 on the branches for three years longer, while on other trees most of the leaves appear to persist until 



1 In exposed positions the branches sometimes lengthen only nia, Muir has found branches thirty-six years old and only an 

 from one eighth to one quarter of an inch during the few weeks eighth of an inch in diameter. 

 of the year when growth is possible ; and on Mt. Shasta, Califor- 2 Coulter & Rose, Bot. Gazette, xi. 260. 



