PINUS ALBICAULIS 
(Pinus flexilis of English Arboriculturists). 
Identification. —PINUS ALBICAULIS, Engelmann in Trans. Acad. Sc. of St. Louis, ii. p. 209 (1863). 
PINUS FLEXILIS, Committee of Oregon Botan. Assoc. (Balfour), in Circular to Subscribers (1852). 
PINUS CEMBROIDES, Newberry in U.S. Pacif. Rail. Expedition, vol. iv., Bot. Rep., p. 44 (1857) not of Zucc. 
PINUS FLEXILIS, var. ALBICAULIS, Engelmann in Botany of California, ii. 124 (1880). 
PINUS SHASTA, Carriere, Traits, ed. 2, p. 390. 
Specific Characters. —Pino Cembrse affinis, foliis quinis, interdum binis ternis vel quaternis, H vel 2 
pollices longitudine; strobilis erectis late ovatis rubro-fuscis, squamis latissimis orbiculato-rhombeis 
apophysi tumido pyramidato, umbone sub-acuto; seminibus apteris. Habitat in montibus in Oregon 
et California. 
Description. —A tree with a spreading top, varying in size according to situation, reaching 50 feet high, 
with a trunk 1 foot in diameter, down to a shrub 3 feet high. High up on the mountains it diminishes 
until it almost creeps along the ground, with a tabular top so compact that a person can walk on it. The 
bark of the trunk is as white as milk, but moderately rough and thin, having (according to Dr. Newberry) 
much the appearance of the bark of the White Oak ( Quercus alba) in trees of moderate size. The bark 
of the branches is loose, spongy, grey, smooth, and tender; the wood of the branches very flexible and 
tough. The leaves (fig. 1) are densely crowded together, confined to the extremities of the branches, 
five in a sheath, but sometimes fewer (two, three, or four), pale bluish-green, triangular and smooth, those 
of each fascicle of uniform length and approximated, giving the foliage a notched or cropped look ; 
they are subserrated, the serrations being at long distances from each other. Beneath the epiderm is a 
thick layer of hypoderm, which is extended round each of the three sub-epidermal resin-canals (fig. 2), 
Fig. 2. Fig. 3. Fig. 4. 
though Engelmann says that the ducts of P. flexilis are destitute of strengthening cells. Male catkins, 
in a specimen collected by Sir J. D. Hooker and Dr. Gray on Mount Shasta, about half-an-inch long, 
oblong, surrounded at the base by overlapping ovate-acute boat-shaped scales; filaments slender, anther 
purplish, connective, straight, or reflexed, crested or reduced to a sharp point. Cones (fig. 3) erect or 
divergent, 
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