thuja PINACE.E 785 



LIBOCEDRUS 



3 THUJA L. Sp. 1002 



Trees with thin fibrous bark, scattered branches and distichous 

 evergreen foliage. Leaves opposite, adnate and imbricated in 4 

 rows, oblong, with free acute tips somewhat dimorphous. Flow- 

 ers monoecious. Aments terminal, of few scales .decussately 

 imbricated in pairs. Staminate flowers numerous, very small, 

 with 3 or 4 anthers under each of the 4 or 6 subpeltate broadly 

 ovate pointed scales. Pollen grains simple. Fertile aments ter- 

 minating stouter branchlets, of 8-12 erect scales, with 2 or more 

 erect ovules at the base of each. Cones soon strongly reflexed, 

 maturing the first season, small, the thin-coriaceous scales ovate, 

 the lowest and uppermost pairs sterile. Seeds lanceolate and 

 somewhat compressed, nearly equally winged. 



T. plicata Don Hort. Cantab, ed. 6, 249. T. gigantea NuU. A tall 

 graceful tree 100-250 feet high and 2-12 feet in diameter at base : foliage light 

 green and shining : leaves ovate, acuminate and subpungent : cones 5-8 

 lines long, ovate, cinnamon-colored, somewhat clustered at the ends of 

 branchlets, the ovate scales with a thin acute usually appressed mucro, the 

 lowest and uppermost pairs sterile, the others with 2-6 ovules : seeds a little 

 shorter than the wings which are 3 lines long, distinct and slightly unequal. 

 Frequent in forests California to Alaska and Idaho. 



4 LIBOCEDRUS Emjl. Syn. Conif. 42. (1847.) 

 Evergreen trees with smooth or fissured bark, scale-like leaves 

 and monoecious or dioecious flowers. Leaves decussately opposite, 

 imbricated by fours and dissimilar, the facial ones smaller, flat 

 and appressed, the marginal ones bract-like and keeled. Aments 

 solitary, terminal : the staminate ones with subpeltate scales, each 

 with 3-4 longitudinally dehiscent anthers on the dorsal side. 

 Fertile aments bracteate, with 4-6 decussately opposite erect 

 scales, the lower pair usually sterile, the third when present con- 

 nate into a longitudinal septum. Ovules 2 to each scale, flask- 

 shaped. Cone ripening the first year, its scales subwoody, mu- 

 cronate below the apex, erect, at length spreading. Seeds in pairs 

 or solitary. Cotyledons two. 



L. decurrens Torr. PI. Fremont 7, t 3. A tall tree 100-150 feet high 

 by 3-7 feet in diameter, with lax scattered spreading branches : leaves 

 bright green, in 2 decussate pairs at each joint, closely adnate except the 

 short acute tip, the lateral without glands and nearly covering the flat- 

 tened obscurely pitted inner ones: staminate flowers ovate, of 12-16 scales: 

 cones 9-12 lines long, scaly-bracted at base, oblong, the lower scales very 

 short, the upper connate into a longitudinal septum, the middle pair 

 convex, obtuse at the tip, all with a short acute somewhat incurved mucro : 

 seeds oblong-lanceolate, 3-6 lines long, the narrow outer wing scarcely 

 longer; the inner one broad and nearly equalling the scale. On dry hill- 

 sides, Oregon to California and Nevada. 



Tribe 2 Taxodinese. Leaves alternate. Scales of the fertile 

 aments more numerous and spirally arranged, in fruit becoming a 

 woody cone. Ovules erect: in some genera inverted. 

 5 SEQUOIA Endl. Syn. Conif. 198. 



Tall trees with straight columnar trunks, short spreading bran- 



