CATALOGUE. 261 



so difficult as Pinus, but I find it impossible to unite it with any other of 

 the allied species. It has the cone of P. ponderosa, especially of that form 

 figured by Torrey as P. deflexa, and, like all forms of that species, it has 

 the peculiarity that the fallen cones, found on the ground, are always 

 imperfect, their lowest part remaining attached to the branch for another 

 season ; I do not know of any other pine with this singular character. 

 But we could not well class this 5-leaved pine with the 3-leaved ponderosa. 

 On the other hand, the form of the cone and its scales will not permit us to 

 refer it to the Mexican P. Montezuma, though the structure of the leaf is 

 very similar to that of this pokymorphous species, which appears to include 

 even P. Hartwcgii. The three parenchymatous ducts of the leaf and the 

 strengthening cells* within the sheath of the vessels are exactly as we find 

 them in Montezuma, and different from ponderosa. 



Pinus ponderosa, Dougl. Parlat. /. c. 305. — A large tree, with large and 

 spreading head, thick, deeply cracked, red-brown bark, and heavy, resinous, 

 yellowish wood ; thick branchlets, rough from leaf-scars and the persistent 

 remnants of bracts ; leaves in twos or mostly in threes, 4-8', in some rare 

 forms 10-12', long, §" wide, with sheaths at first 1' long, when old with- 

 ering to 2 or 3" long; staminate flowers cylindric, with an involucre of 10 

 or 12 scales, the lowest pair of which is about two-thirds as long as the 

 innermost ; anthers with a large sub-orbicular crest ; fertile aments sub- 

 terminal ; patulous cones oval or rarely elongated, very variable in size, 

 2-G' long ; knob of the scales more or less prominent, and in some forms 

 even recurved, bearing a rather stout prickle ; seeds black, ridged on the 

 lower side, wing broadest in the middle ; cotyledons 6-8, or in the largest 

 seeds as many as 10. 



Colorado, New Mexico, and Arizona, extending through the Northern 

 Rocky Mountains and adjacent regions to Oregon and California, mostly in 

 the middle altitudes ; the most common and most useful timber of many 



•This uaino has been given to longitudinal cells with very thick wally, destitute of chlorophyll, 

 which are characteristic of most pine-leaves, anil by their different disposition aid in distinguishing them 

 from one another. Tbey are generally arranged close, to the epidermis, and especially in the angles of 

 the leaves, aud bavo usually about the samo diameter as the epidermis-cells themselves. We find them 

 also occasionally surrounding tbe ducts, c. tj. in P. ponderosa, also in the Cembroid Pines aud in P. Bal- 

 fouriana and /'. aristata; while in P. fieri Ih they always leave the ducts free, a character by which 

 we can readily distinguish the leaves of tin se species, otherwise so similar. Not rarely arc they found 

 within the sheath, strengthening, as it seems, the ceutre of tbe leaf. 



