666 , Order 123.— SAUEURACBjE. ' 



long and of equal or greater -width), dark green, petioles 2 to 3' long and laterally 

 oompreased, so that they can scarcely remain at rest in any position, and are 

 thrown into excessive agitation by the slightest breeze. The trembling of the 

 " aspen leaf" is proverbial. Aments plumed with silken hairs, about 2' long, 

 , pendulous. Apr. 



4 P. grandident^ta Mx. Large Poplar. Lvs. roundish-ovate, acute, uJtiA 

 large, unequal, sinuate teeth, smooth, villous when young ; bracts fan-shaped, 5-cleft 

 and silky-fringed. — Woods and groves, Can. .and Nor. TJ. S. not uncommon. 

 St. 40f high, with a diam. of If, straight, covered with a smooth, greenish bark. 

 Branches distant, coarse and crooked, clothed with leaves only at their ex- 

 tremities, with terete twigs. Lva. 3 to 5' long and nearly as wide, clothed 

 with thick white down in spring, but becoming perfectly smooth. Aments 3 to 

 4' long, all the parts hairy, the sterUo longer than the fertile. Stam. about 12, 

 as in the preceding species. May. 



5 P. heteroph^lla L. Cotton Tree. Branches terete; li's. roundish-ovate, 

 obtuse, unoinately serrate, cordate at base, the small auriculaie lobes over-dosed, 

 white-tomentous when, young, at length nearly smooth ; ovaries with a long pedicel 

 and conspicuous style. — Swamps, S. Eng. (rare) to 111. and La. A tree 40 to 60f 

 high, trunk 1 to 2f diam. Lvs. 3 to 6' long, with small teeth, blunt or never 

 acuminate at apex, and the base lobes often so overlapping as to conceal tho 

 insertion of the petiole. Apr., May. 



5 P. balsamifera L. Balsam Poplar. Taoamehao. Branches terete ; lvs. ovate, 

 acuminate, with close-pressed serratures, white and reticulate-veiny_ beneath, 

 glabrous both sides ; bracts of the ament dilated, laciniate-fringed, slightly hairy ; 

 stam. 40 to 50. — Swamps and river banks. Me. to Penu., N. Y., Can. and the N. 

 W. coast. A large tree, 40 to 80f high, trunk 1 to 2f diam. Lvs. 2 to 4' long. 

 Sterile aments 2 to 3' long, fertile at length 4 to 6'. Stam. purple. Buds in spring 

 covered with an aromatic resin which may be separated in boiling water. 



7 P. cdndloans Ait. Balm of G-ilbad. (Pig. 268, 269). Branches terete, lvs. 

 ovate, cordate, acuminate, closely and unequally serrate, whitish and reticulate- 

 veined beneath, petiole hirsute; bracts of the ament oval, laciniate-fringed; stam. 

 about 20. — A fine tree of strong and peculiar fragrance, often cultivated, rarely 

 growing v/Hd, Can. and the Northern TJ. 8. Heiglit 30 to SOfJ with a pyramidal 

 head of dense ample foliage. Lvs. 4 to 6' long, at length smooth and dark green 

 above. SterUe aments 2 to 3' long, fertile 4 to 6. Buds fiEed throughout with 

 fragrant resin. 



8 P. nigra L. /?. EETtrLipfiLiA Torr. Black Poplar. Young branches pubes- 

 cent ; lvs. deltoid^rhombic, conspicuously acuminate, finely crenate-serrate, smooth 

 both sides; aments witliout hairs. — Trees 30 to iof high, planted at Hoboken, 

 N. J. and perhaps in Penn. -f Eur. (P. betulifolia Ph. P. Hudsonica Mx.) 



9 P. dilatkta Ait. Lombardt Poplar. Lvs. smooth, acuminate, deltoid, 

 aerrate, the breadth equaling or exceeding the length ; trunk lobed and sulcate. — 

 Early brought to this country, and has been planted about many a dwelling and 

 in village streets. Its rapid growth is the only commendable quality it possesses, 

 while the huge worms by which it is often infested render it a uuisanca 

 t Italy. 



10 P. dlba L. Abele. Silver-leaf Poplar. Lvs. cordate, broad-ovate, 

 lobed and toothed, acuminate, dark green and smooth above, very wliite-downy 

 beneath ; fertile aments ovate ; stig. 4. — A highly ornamental, cultivated tree. 

 Nothing can be more striking than the contrast between the upper and lower 

 surface of the leaves, f Bur. 



Order CXXIH. SAIJRURACEtE. Saurdrads. 



Berbs with jointed stems, alternate, entire leaves furnished with stipules. Floa- 

 ers in spikes, perfect, naked, having neither corolla nor calyx. Stamens definite. 

 Ovaries 3 to 5, more or less tmitod. /Seeds ascending. Embryo enclosed in a sac 

 (amnios), outsido of hard, mealy albumen. Fig. 264. 



