coNiFERiE. SILVA OF NORTH AMERICA. 83 



PSEUDOTSUGA. 



Flowers solitary, naked, monoecious ; the staminate axillary, stamens indefinite, 

 anther-cells 2, surmounted by a short spur ; the pistillate terminal or axillary, their 

 bracts elongated, 2-lobed, aristate, ovules 2 under each scale. Fruit a woody strobile 

 maturing in one season. Leaves flat, petiolate, persistent. 



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Pseudotsuga, Carriere, TraiU Conif, ed. 2, 256 (1867). — Tsnga (sect. Peucoides), Engelmann, Trans. St. Louis Acad. 

 Bentham & Hooker, Gen. iii. 441. — Masters, tTour. Linn. ii. 211 (1863). — Eichler, Engler & Prantl Pflanzenfam. 



Soc. XXX. 35. 



ii, pt. i. 80 (in part). 



Abies (sect. Peucoides), Spach, Hist. Veg. xi. 423 (1842). Pinus, Baillon, Hist. Fl. xii. 44 (in part) (1892). 



Pinus (sect. Tsuga), Endlicher, Gen. SuppL iv. pt. ii. 6 (in 

 part) (1847). 



Pyramidal trees, with thick deeply furrowed scaly hart, hard strong yellow or red wood with 

 spirally marked wood cells and broad dark resinous bands of small summer cells often occupying half 

 the width of the layers of annual growth, slender usually horizontal irregularly whorled branches clothed 

 with slender spreading pendent or rarely erect lateral branchlets forming broad flat-topped masses of 

 foliage, stout wide-spreading roots, and thin tough rootlets. Branch-buds formed in early summer, 

 ovate, acute, from three to five in number, the lateral in the axils of upper leaves and much smaller than 

 the terminal bud, covered with numerous closely imbricated dark chestnut-brown spirally disposed scales 

 rounded, entire, or somewhat erose on the thin often scarious margins, increasing in size from the bottom 

 of the bud upward, the two outer minute, lateral, and opposite, the inner thin, accrescent, silvery white, 

 withering and sometimes persistent on the base of the branch for three or four years and in falling 

 marking it with ring-like scars. Leaves densely crowded in short clusters when they first emerge from 

 the bud, spirally disposed but often appearing two-ranked on vigorous sterile branches by the twisting 

 of their slender petioles, spreading nearly at right angles with the branch, straight or more or less 

 incurved, flat, rounded and obtuse or acuminate at the callous apex, marked on the upper surface 

 with a conspicuous groove and on the lower surface with a band of numerous rows of stomata on each 

 side of the prominent midrib, containing two lateral resin ducts close to the epidermis on the lower 

 side, articulate on low transversely oval concave ultimately woody pulvini, persistent for many years 

 and in drying. Flowers appearing in early spring from buds formed the previous summer on branches 

 of the year, erect, surrounded by conspicuous involucres of the lustrous oblong bud-scales rounded 

 at the apex, increasing in size from below upward, the inner becoming much enlarged and silvery 

 white. Staminate flowers axillary and scattered along the branchlets, oblong-cylindrical, raised on 

 short, ultimately elongated stalks, composed of numerous spirally arranged short-stalked globose anthers 

 opening obliquely, their connectives terminating in short spurs; pollen-grains ovoid, subglobose, 

 without air-sacs.* Pistillate flowers terminal or in the axils of upper leaves, short-stalked, oblong, 

 composed of numerous ovate rounded spirally imbricated scales much shorter than their narrow acutely 

 two-lobed bracts variously laciniately cut on the margins, with midribs produced into elongated slender 

 tips; ovules two under each scale, inverted, collateral. Cones maturing in one season, ovate-oblong, 

 acute at the apex, rounded at the slightly narrowed base, pendulous on stout peduncles clothed with 

 linear-acute bracts, their scales rounded, concave, rigid, decreasing in size and sterile at both ends of the 

 cone, spreading at maturity almost at right angles with its axis, persistent ; bracts exserted, two-lobed, 

 the lobes spreading, acuminate, their prominent midribs produced into long stifE linear lanceolate 



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^ Engelmann, Brewer ^ Watson Bot Cal. ii. 119. 



