22 The Pines 



becoming almost black. The branch-buds are cylindric, abruptly taper-pointed, 

 about 2.5 cm. long, or the lateral less than half this size. The leaves are in 

 fascicles of 5, the large persistent sheath 2 to 4 cm. long; they are dark green, 

 slender, 1.5 to 3 dm. long, sharp, thick-tipped, and minutely toothed near the apex, 

 marked on all faces with many rows of stomata and containing 3 resin passages 

 and 2 fibrovascular bundles. They grow in large tufts at the ends of the twigs 

 and persist for several years. The flowers appear from Januar)^ to March, the 

 staminate in short crowded head-like clusters, cyhndric, 2.5 to 4 cm. long, about 

 8 mm. thick, their anthers yellow; the pistillate flowers are nearly terminal, in 

 pairs, stout-stalked, oblong-oval, 18 mm. long, about 12 mm. thick; scales broadly 

 oval, gradually narrowed into a stout point. The young cones are ovoid, 6 to 7.5 

 cm. long, brown, with thick red-brown recurved scales, maturing the third autumn, 

 when they are stout-stalked, spreading, broadly ovoid, i to 1.5 dm. long, dark 

 brown, and soon discharge some of their seeds, but retaining many until they drop 

 off the tree, a year later; the scales are thick, about 3 cm. wide, prominently 4- 

 angled, and thickened into a central knob which is terminated by a stout angled 

 straight or recurved spine. The seeds are oval, 18 to 25 mm. long, somewhat 

 angular, dull brown, with lighter markings on the upper side; endosperm sweet 

 and oily; the wing has a thickened rim almost encircling the seed, is dark brown, 

 very broad at apex and extends about 10 mm. beyond the seed, from which it 

 separates as readily as it does from the cone-scale; cotyledons 13 or 14. 



The wood is soft, weak, and brittle, close-grained and light red; its specific 

 gravity is about 0.49. It is used for fuel; the seeds are also gathered and eaten 

 by Indians, like those of the nut pines. 



15. ARIZONA YELLOW PINE Pinus arizonica Engelmann 



A tree of the higher mountain slopes of southern Arizona, and abundant in 

 the mountains of northern Mexico ; its maximum height is 30 meters, with a trunk 

 diameter of 1.2 meters. Also called Arizona pine. 



The trunk is tall and thick. The branches are stout and spreading, often 

 irregular, forming a narrow conic or irregular round-topped head. The bark is 

 up to 5 cm. thick and fissured into large irregular plates with close light reddish 

 brown scales; on younger stems it is much thinner. The twigs are stout, dark 

 yellowish brown at first, often becoming lighter colored for a time but finally dark 

 grayish brown and roughened by the persistent bases of the bud-scales. The 

 branch-buds are about 10 mm. long, ovoid, sharp-pointed, and closely covered by 

 dark brown, fringed scales. The leaves are in fascicles of 5 or sometimes 3, 

 dark green, slender, stiff, 12 to 18 cm. long, with short sharp, thick tips and 

 small teeth at least toward the apex, and contain 2 fibrovascular bundles; they 

 are densely tufted near the end of the twigs and persist for about three years. 

 The flowers appear in spring, the staminate in clusters near the tips of the twigs, 

 oval, 18 to 25 mm. long, their anthers dark purple. The pistillate flowers are 



