CATALOGUE. 257 



Pseudotsuga* Douglasii, Carriere ; Abies Douglasii, Lindl. — Often 

 one of the tallest trees known (in favorable localities, in Oregon, even 

 300-350 feet high), with very thick, much cracked, brown bark, spread- 

 ing branches, conspicuous, somewhat persistent bud-scales, slender, flat, 

 linear, obtuse or acutish leaves, f-lq, rarely \\ inches long; cones ovate- 

 oblong, usually 2-3' long, brown, well marked by the protruding, long- 

 cuspidate bracts; scales orbicular, concave; oval wings about as long as 

 the somewhat triangular, pale seeds; cotyledons 6-8. 



Common through Arizona, as it is through all the western mountain 

 regions, down into Mexico. — Leaves stomatose and whitish only on 

 the lower surface, with 2 resin-ducts close to the epidermis of the under 

 side. 



PiNUSf flexilis, James; Parlat. in DC. Prod. 16, 2, 403. — A middle- 

 sized tree, with a smoothish, or, in old trees, lightly furrowed, pale or ash-gray 

 bark; leaves in fives, mostly entire and smooth-edged, 1^-2' long, in a loose, 

 deciduous sheath, about £' in length ; involucre of the oval staminate flowers 

 composed of 8-9 oval, obtuse scales; anthers with a short lacerate or toothed 

 crest; cones sub-terminal, J spreading, or slightly reflexed, ovate-cylindrical, 



* Pseudotsuga, Carr. Conif. ed. 2, 25G; Abies, sect. Tsuga (in part), Endl. — Coniferous trees, with 

 flattened, entire, somewhat 2-ranked, distinctly petioled leaves, leaving on the hranchlots scarcely 

 prominent, transversely oval scars; flowering from the axils of the leaves of the previous year; staminate 

 flowers resembling an oval or subcylindrical anient; anthers with a recurved, spurlike point; cells 

 openiug longitudinally; pollen oval-subglobose : sessile cones subpeudulous, maturing in one season ; 

 scales and their much elougated bracts persistent on their axis; seeds without balsam-vesicles, not 

 separating from the wing. — Very large trees, with very thick bark and reddish or yellowish wood, of 

 secondary value, which is characterized and well distinguished from the wood of all the allied genera, 

 and of most coniferous woods, by the abuudauco of spiral vessels, otherwise so rare in this family. The 

 difference in the pollen, the seeds, and the leaf structnro make a separation of this genus from Allies as 

 well as from Tsuga necessary. 



t To the character of the genus Pinus may be added : Staminate flowers surrounded by an involu- 

 crum, of a somewhat definite number of scales (3-15 or 20), the lowest, lateral, pair of which are strongly 

 keeled; pollen-grains lobed, similar to that of Abies and Picca, but only half as large, 0.04-0.06 min wide. 

 The bracts of the cones, which, in the allied genera, remain membranaceous, become here much thickened 

 and corky, and, together with the scale below them, form a sort of cell for the reception of the seeds. The 

 base of the wing only partially covers the upper side of the seed, and usually forms a mere rim around the 

 seed, which easily separates from it; in a few species, the wing is firmly attached to the seed, and in a 

 few others it is reduced to a narrow margin ; the seed never shows balsam-vesicbs. 



t The fertile ameuts of Pinus, and consequently the cones, are usually called terminal, but they 

 never are that, but always lateral, and either appeal between the uppermost leaves and the terminal 

 bud, when they may be called sub-terminal (P. resivosa, Strobus, sylvestris), or the axis continues to 

 elongate after the formation of the aments, when these and consequently the cones become lateral, the 

 axis bearing leaves and sometimes other aiaents above them (P. Teedu, and especially inops, and in 

 Europe, /'. Balepeiais). In some species both forms occur, or only a few leaf-bundles intervene between 

 17 BOT 



