350 CONIFERZ OF WHEELER’S EXPEDITION. 
parts of that district and generally known there as “ yellow pine.” A most variable tree, several forms of which [262] 
have received distinct specific appellations, but the specimens collected in these expeditions all appear to belong 
to the ordinary smaller-leaved and smaller-fruited form. Whenever the macroscopic characters leave any doubt, the 
microscopic structure of the leaf appears to offer a sure guide. The leaves contain two or three or often more paren- 
chymatous resin-ducts, usually of uncommonly small diameter, always with some, and often surrounded by many, of 
those strengthening cells of which I have spoken before ; the same cells occur within the sheath, above and below the 
bundles of vessels. I have examined the leaves of 20-30 specimens from the whole range of the species, and have 
never failed to discover this same structure, which I must therefore consider as characteristic of the species. 
Pinus CHIHUAHUANA, Engelm. in Wislizen. Mem. note 26 ; Parlat. l. c. 397. — A middle-sized tree, with ternate, 
closely serrulate leaves 24-4 inches long ; the loose glistening sheaths } inch long, deciduous after the first season ; stami- 
nate flowers slender, cylindric, about } inch long, sometimes interspersed among the foliage ; involucre as long as the 
nearly entire-margined bract, of 8-10 scales, the outer about half as long as the inner ones ; anthers with an almost orbi- 
cular a ns cones sub-terminal, small, 14 inches long ; knobs of the scales bearing recurved, deciduous prickles. 
n Arizona, in Sanoita Valley, at 6,500 feet altitude, Rothrock (649), in 1874 ; also Wright, and in Western 
Dukes, ‘Wislizenus —A tree 30-50 feet high, “ with bark resembling yellow pine ;” easily distinguished by the 
characters given, and especially by its deciduous sheaths. All the Strobi and Cembroids have such deciduous sheaths, but 
among the Pinasters the sheaths are persistent, except in one or two Mexican species, in P. Bungeana, above mentioned, 
and in this species. Leaves strongly and closely serrulate, and with three or often four parenchymatous ducts. 
Pinus contorta, Dougl., var. LATIFOLIA, Engelm. P. Murrayana, Balf. Oreg. Com. Rep. — A middle-sized 
tree, sometimes 60-80 feet high, and 2-4 feet in diameter, with thin, scaly bark of grayish to red-brown color, and 
close, white, rather soft wood ; leaves in pairs, 14-2 inches or rarely 3 inches long and 1 line wide ; staminate 
flowers oblong, 6 lines in length, their involucre commonly of 6 scales; crest of the anthers sctanhad pistillate [263] 
aments subterminal, their scales with erect or spreading points ; cones oval, usually very olilique; and often 
curved, reflexed, 13-2 inches long; scales, especially the lower ones, with largely developed pyramidal knobs in the 
centre, much smaller on the inner side, armed with strong or sometimes slender, awnlike prickles ; seeds black, rough, 
ridged on the lower side; wing widest below the middle ; cotyledons usua 
Southern Gstornio to California, apparently not noticed in Arizona. . valuable timber tree of the northern 
mountain regions, forming large forests in the higher altitudes of the Rocky and California mountains, reaching into 
the British Possessions. The colical form, discovered by Douglas near the mouth of the Columbia River (P. Bo landert, 
rlat.), is a seaside tree, extending up and down the coast, resisting the ocean storms, as does P. Halepensis those of 
the Mediterranean, and protecting the inside vegetation ; it is distinguished by its low, beneran and often shrubby 
growth (whence probably the name), and its slender leaves, not more than 4-2 lines wide ; northward, in British 
Columbia and Alaska, both forms completely run together. The species was formerly confounded with the eastern 
. tnops, which differs by its lateral, more or less pedunculated cones ; it is more closely allied with the Northern P. 
Banksiana, which, however, bears its scarcely prickly or entirely unarmed, mostly a rarely sub-terminal, cones 
erect or patulous, never recurved : a very unusual occurrence among pines. The cones of the Rocky Mountain batt 
and also those of the seaside scrub, are usually persistent for many years, and ee remain closed after maturity 
—— while in the variety of the Sierras, they appear to open on maturity, and to drop before the leonoex 
season, as Prof. C. 5. Pent nt observed, 
JUNI s Vir a, Linn. ; Engelm. American Junip. in Trans. Ac. St. Louis, 3, 591. —Santa Fé, N. Mex. 
‘detooket in ares pte abaaatiy picceceet by its slender branchlets and leaves with entire margins. 
JUNIPERUS OCCIDENTALIS, Hook., var. MonosPERMA, Engelm. Junip. 590. — A small tree or a bush, with fibrous 
bark, squarrose branches; and obtuse, minutely denticulate leaves in twos and threes; berries globose, blue-black, or 
sometimes copper-colored, 3-5 lines thick, resinous, pulpy ; seeds 1 or 2 
Chiricahua Agency, Arizona, Rothrock. A form common from Souther Colorado to New Mexico and [264] 
westward ; distinguished from the original J. occidentalis of Oregon and California by its more squarrose growt. 
thinner branches, and smaller fruit. 
JUNIPERUS PACHYPHLE@A, Torr. Bot. Whipp. in Pacific. R. R. Rep. 4, 142; Engelm. l. c. 589.—A middle-sized 
tree, with spreading head and thick, fissured bark ; branchlets ae leaves elongated, often resiniferous on the 
back, with slightly seareerae margins ; berries large, glaucous, man 
An im n Western New Mexico (Fort Wingate, thethcode number 140, in 1874) and Northern 
Arizona ; readily Seciided from all the other species by its bark, which Dr. Rothrock compares with that of the 
white oak, and others with the bark of pine. 
Juniperus Carirornica, Carr., var. UTAHENSIs, Engelm. Junip. 588.— More slender than the western type, 
J. Californica, with thinner branches and smaller, not so strongly fringed leaves, often in twos ; smaller, more globgse 
berries ; embryo with 5 cotyledons, as in the species. 
Camp Apache, Arizona, Gilbert, Rothrock. 
