ON PINUS ARISTATA, ETC. 329 
tree, usually 30-50 feet high, though Fendler, a good authority, saw it near Santa Fé 60-80 feet high; Dr. Bigelow’s 
trees, of the height of 100-130 feet, on the San Francisco Mountain (Bot. Whipple, p. 20), must belong to some 
other 5-leaved species. In Colorado it is a fine tree, with tapering trunk and oval outline, branching almost [209] 
om the base, lower branches 
horizontal, upper ones ascending ; 
wood white, hard, annual rings 
from } to } line, on an average $ 
line wide ; trees become in 250- 
300 years about 1 foot thick. 
Leaves crowded towards the end 
of the very flexible branches, per- 
sistent 5 or 6 years, usually 13-23, 
very rarely 1 or 3 inches long; 
sheaths similar to those of P. Stro- 
bus or P. Cembra, 8 lines long, 
deciduous. Male aments 4-5 lines 
long, forming a thick spike 10-12 
lines long, cones subcylindric, ta- 
pering to the end, 4-5 inches long, 
2 inches in the largest diameter, on 
short peduncles; scales 12-14 lines 
long, 10-12 lines wide, squarrose ; 
lowest sterile ones recurved ; fer- 
tile ones with deep impressions for 
the reception of the seeds both on 
the upper inner side and on the 
back, the latter cavities partly 
formed by the large (4-6 lines 
long) ligneous or rather corky { 
‘ bract. Seeds 4-5, rarely 6 lines 
; long, irregularly ovate or obovate ; 
wing minute, not deciduous nor 
adhering to the scale, as in P. 
Cembra, P. edulis, etc., but reduced 
to a persistent keel on the upper 
end and outer edge of the seed; 
embryo with 8 or rarely 9 cotyle- 
dons 
PINUS ALBICAULIS. P. cembrot- 
des, Newberry, Pac. R. R. Rep. 6, 
Bot., p. 44, c. tc. non Zucc., an 
alpine species from the Cascade 
Mountains, in Oregon, may be 
a western form of this species, 
though I am inclined to consider 
it as different, and intermediate 
between P. flexilis and P. Cembra, 
distinguished by the pubescent 
branchlets, few scattered teeth on 
the edges of the leaves, and es- Puate VI. — Prnvs aristata (p. 327). 
pecially by the short oval cones 
with thick squarrose scales pointed with a knob. The name is suggested by the color of the bark of the tree, which is 
‘*as white as milk.” 
While studying the Coniferz of the Rocky Mountains, I was led to investigate the characters of 
the different types which Linnzus had comprised in his genus Pinus, The great master himself had 
at one time thought proper to divide that rather incongruous mass, considering Abies as distinct 
