179] ENGEILMANN—REVISION OF THE GENUS PINUS, ETC. 19 
6. P. Balfouriana, Jeffrey, and P. aristata, Engelm., of the Colorado 
Rocky Mountains, are identical in leaf-structure and in flowers and must 
be united, tho he cone of the former is elongated, often even cylindri- 
cal, the apophyses thicker and peculiarly spongy, and at maturity unarm- 
ed, ile th oval co h thinner scales and awnlike 
prickles. In Ut d Nevada a form ith es like the latter, 
con 
but with short, stout, recurved prickles. eine enumerates aristata, 
but does not mention Balfouriana. 
7. P. Khasia, Royle, and its two allies, form a very natural little group. 
Leaves in this species with 2 dorsal ducts; strengthening cells very slight 
Ree anthers } to 1 line long; crest only 4 line wide, nearly en 
nsularis, Endl., has similar leaves, ducts often indistinct, sie 
about 8, outer pair more than half as long as the inner ones; anthers less 
than 1 line long, crest nearly entire. 
P. longifolia, Roxb. Ducts few (in Wallich’s rea ). or many (in 
Hooker and Thompson’s), or none at all er’s; Thuret’s cult.); 
strengthening cells strongly developed in wham all around leaf; bracts 
pits strongly fringed, deciduous; male flowers larger than in last, 1-14 
nches long, thicker; anthers 1} aes long; crest } line wide, strongly 
Silo de nticclaes involucre not seen. The thick bundles of strengthen- 
ing cells and the larger male flowers readily distinguish it from the two 
others. 
ontana, Duroi, is so well characterized that it is inconceivable 
how it could have been taken for a variety of P. sylvestris, unless some 
hybrid forms, which are said to occur, have created the difficulty. The 
involucral bracts are always more numerous, usually about 6, the anthers 
crested, the female aments subsessile, and the young cone erect; in sylves- 
tris the involucral bracts rarely exceed 3, the crest of the anthers is reduced 
to a small ridge or a few teeth, the female ament is not longer than its a 
duncle and becomes recurved soon after flow ring. 
g. P. resinosa, Ait., is the only American representative this well 
enaracteried group. The 6 involucral scales are articulated in the middle, 
e upper part fling off early (p. 168); ducts almost always say 2 on the 
agate side of the 
I coir, Sieb. & Zucc. Leaves with numerous ducts, mostly 
sg eae by strengthening cells, also some of these within the sheath; 
in a few mar May in Japanese as well as in cultivated specimens, the 
strengthening cells are almost wanting; male flowers Apa seg 2 to 3 lines 
long, in an elongated spike; involucrum of 3 or 40 r 6 bra 
of equal length; anthers only 4 line long, or less, vies a small, slightly 
denticulate crest. Only in Japan. Sometimes cultivated under the name 
of the following. : 
