coniferje. 8ILVA OF NORTH AMERICA. 85 



PINUS CHIHUAHUANA. 



Yellow Pine. 



Leaves in 3-leaved clusters, slender, pale green, from 2J to 4 inches in length, 

 their sheaths deciduous. Cones broadly ovate, from 1| to 2 inches long, maturing at 

 the end of the third season, their scales slightly thickened, furnished with small 

 recurved deciduous prickles. 



Pinus Chihuahuana, Engelmann, Wislizenus Memoir of Nadelh. 86, 416. — Hoopes, Evergreens, 143. — Parla- 

 a Tour to Northern Mexico (Senate Doc. 1848), Bot. tore, Be Candolle Prodr. xvi. pt. ii. 397. — Sargent, 

 Appx. 103 (1848) ; Bothrock Wheeler's Hep. vi. 262 ; Forest Trees N. Am. 10th Census U. S. ix. 194. — Mayr, 

 Trans. St. Louis Acad. iv. 181. — Lindley & Gordon, Wald. Nordam. 237, t. 8, f. — Beissner, Handb. Nadelh. 

 Jour. Sort. Soc. Lond. v. 220. — Carriere, Rev. Hort. 258. — Masters, Jour. B. Hort. Soc. xiv. 227. — Koehne, 

 1854, 227 ; Fl. des Serres, ix. 200 ; Traite Conif. 357. — Deutsche Dendr. 34. — Lemmon, West-American Cone- 

 Gordon, Pinetum, 193. — Henkel & Hochstetter, Syn. Bearers, 4A. 



A tree, in the United States rarely more than forty or fifty feet in height, with a tall trunk 

 sometimes two feet in diameter, and stout slightly ascending branches forming a narrow open pyramidal 

 or round-topped head of thin pale foliage. 1 The bark of the trunk is from three quarters of an inch 

 to an inch and a half in thickness, and is dark reddish brown or sometimes nearly black and deeply 

 divided into broad flat ridges covered with thin closely appressed scales. The branchlets are slender, 

 glabrous, bright orange-brown when they first appear, soon becoming dull red-brown, and during their 

 first summer much roughened by the large persistent reflexed bases of the scales of the leaf-buds, 

 which mostly fall during their first winter, although their scars do not entirely disappear for many 

 years. The winter branch-buds are ovate, acute, from one quarter to one third of an inch in length, 

 and covered by dark orange-brown scales with scarious more or less fringed margins. The leaves are 

 borne in clusters of three, with loose chestnut-brown lustrous sheaths usually about half an inch long 

 and deciduous during their first autumn ; they are slender, acute with short callous tips, sharply 

 serrulate, pale glaucous green, and conspicuously stomatiferous with from six to eight rows of stomata 

 on each face ; they contain two fibro-vascular bundles and two parenchymatous resin passages sur- 

 rounded by strengthening cells, which also occur under the epidermis, usually in a single often 

 interrupted layer, and begin to fall during their fourth season. The flowers appear in Arizona in 

 July, the staminate in short crowded clusters, the pistillate generally in pairs on slender peduncles 

 about a quarter of an inch in length and covered by ovate acute dark chestnut-brown bracts. The 

 staminate flowers are oval, from one quarter to one third of an inch long, with yellow anthers termi- 

 nating in conspicuous nearly orbicular crests slightly undulate on the margins, and are surrounded by 

 ten involucral bracts. The pistillate flowers are oval, one third of an inch long, with broadly ovate 

 yellow-green scales gradually contracted into long slender tips erect above and reflexed below the 

 middle of the flower. During their first winter the young cones are erect and from one third to 

 nearly one half of an inch in length ; the following autumn they are horizontal or slightly pendulous, 

 subglobose, and almost an inch in diameter, and when they mature a year later they are broadly ovate, 

 acute, dark green, from an inch and a half to two inches long, and nearly horizontal or occasionally 

 slightly ascending and raised on slender rigid naked peduncles from one third to one quarter of an 

 inch in length ; their thin flat scales, which are about a quarter of an inch wide, are only slightly 



1 See Tourney, Garden and Forest, viii. 22, f . 3. 



