conifers. SILVA OF NORTH AMERICA. 51 



PINUS MONOPHYLLA. 

 Nut Pine. Pinon. 



Leaves solitary or rarely in 2-leaved clusters, stout, rigid, spinescent, from 1 J to 2J 

 inches in length. Cones from 1 J to 2 i inches long. 



Pinus monophylla, Torrey, FrSmonfs Bep. 319, t. 4 Beissner, Handb. Nadelh. 254. — Hansen, Jour. B. Hort. 



(1845). — Bolander, Proc. Cal. Acad. iii. 318. — Parla- Soc. xiv. 375 (Pinetum Danicum). — Coville, Contrib. 



tore, De Candolle Prodr. xvi. pt. ii. 378. — Lawson, Pine- U. S. Nat. Herb. iv. 222 (Bot. Death Valley Exped.). — 



turn Brit. i. 65, t. 9, f. 1-12. — Watson, King's Bep. v. Koehne, Deutsche Dendr. 33. 



330. — K. Koch, Dendr. ii. pt. ii. 271. — Rothrock, PI. Pinus Premontiana, Endlicher, Syn. Conif. 183 (1847).— 



Wheeler, 28, 50. — Engelmann, Bothrock Wheele?*'s Bep. Lawson & Son, List No. 10, Abietinece, 45. — Dietrich, 



vi. 259, 375 ; Trans. St. Louis Acad. iv. 178 ; Brewer & Syn. v. 401. — Gordon, Jour. Hort. Soc. Lond. iv. 293, 



Watson Bot. Cal. ii. 124. — Masters, Gard. Chron. n. ser. f . ; Pinetum, 194. — Knight, Syn. Conif. 28. — Lind- 



xx. 48, f. 8 ; Jour. B. Hort. Soc. xiv. 234. — Sargent, ley & Gordon, Jour. Hort. Soc. Lond. v. 216. — Car- 



Forest Trees N. Am. 10th Census U. S. ix. 190. — riere, Traite Conif. 406. — Henkel & Hochstetter, Syn. 



Lauche, Deutsche Dendr. ed. 2, 104. — Lemmon, Bep. Nadelh. 62. — (Nelson) Senilis, Pinacece, 112. — Hoopes, 



California State Board Forestry, ii. 72, 88 (Pines of the Evergreens, 122. — Hansen, Jour. B. Hort. Soc. xiv. 361 



Pacific Slope) ; West-American Cone-Bearers, 27. — (Pinetum Danicum). 



Steele, Proc. Am. Pharm. Assoc. 1889, 234 (The Pines Pinus edulis, var. monophylla, Torrey, Ives' Bep. pt. iv. 



of California). — Mayr, Wold. Nordam. 241, t. 7, f. — 28 (1860). 



A tree, usually fifteen or twenty, but occasionally from forty to fifty feet in height, with a short 

 trunk rarely more than a foot in diameter, and often divided near the ground into several stout 

 spreading stems. The short thick branches form, while the tree is young, a broad rather compact pyra- 

 mid, and in old age, when they frequently become pendulous, a low round-topped and often picturesque 

 head. The bark of the trunk is about three quarters of an inch in thickness, and is divided by deep 

 irregular fissures into narrow connected flat ridges broken on the surface into thin closely appressed 

 light or dark brown scales tinged with red or orange-color. The branch-buds are ovate, obtuse, about a 

 quarter of an inch long, and covered by pale chestnut-brown scales. The branchlets are stout, and 

 before the lengthening leaves emerge from the leaf-buds are hidden under the closely imbricated scales 

 of the branch-buds ; during their first winter they are light orange-color and then become light brown, 

 gray, or brown tinged with green or orange-color, and at the end of three or four years dark brown. 

 The primary leaves, which are the only ones produced during the first five or six years in the life of 

 the plant, are linear-lanceolate, entire, strongly keeled, glaucous, and from three quarters of an inch to 

 an inch in length, gradually becoming shorter as the buds of the earliest leaf-clusters are developed in 

 their axils ; * the secondary leaves are solitary and terete, or occasionally in two-leaved clusters and 

 semiterete ; they are rigid, incurved, entire, spinescent with long callous tips, pale glaucous green, and 

 usually about an inch and a half long, although sometimes from one and a quarter to two and a quarter 

 inches in length, with loose sheaths from a quarter to nearly half an inch long, the thin tips of the 

 scales soon becoming much reflexed, and, when they fall, leaving the persistent bases of the sheaths ; 

 they are marked with from eighteen to twenty-six rows of stomata, and contain two or three resin ducts 

 and a single fibro-vascular bundle ; 2 the leaves sometimes begin to fall during their fourth and fifth 



1 Gard. Chron. u. ser. xx. f. 8. clusters (Meehan, Proc. Phil. Acad. 1884, 295 ; Bull. Torrey Bot. 



2 The solitary terete leaf of Pinus monophylla was formerly usu- Club, xii. 81. — Hooker f. Gard. Chron. n. ser. xxvi. 136, f. 24). 

 ally thought to consist of a pair of connate leaves, and this hypothe- But the internal structure of the leaf with its single fibro-vascular 

 sis appeared reasonable as the trees occasionally bear two-leaved bundle shows that it is really one leaf, and the apparent anomaly 



