656 Okdeb 123— SAURURAOEJE. 



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

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

 thrown into excesaiye 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. Larhb Poplar. Lvs. roundish-ovate, aiyaie, wUh 

 large, umqual, sinuate teeth, smooth, villous when young ; bracts fan-shaped, 5-dleft 

 and silky-fringed. — "Woods and groves, Can. and Nor. U. 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 tw^s. Lvs. 3 to 5' long and nearly as wide, clothed 

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

 i' long, all the parts hairy, the sterEe longer than the fertile. Stam. about 12, 

 as in tlie preceding species. May. 



5 P. heteroph^Ua L. Cotton Tree. Branches terete; lvs. roundish-ovate, 

 obtuse, uncinately serrate, cordate ai iase, the small auriculaie lobes over-dosed, 

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

 and conspicuous style. — Swamps, S. Bng. (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 the 

 insertion of the petiole. Apr., May. 



5 P. balsamffera L. Balsam Poplar. Taoamehac. Branches terete ; lvs. ovate, 

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

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

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

 TV. 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 G'. Stam. purple. Buds in spring 

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



7 P. candicans Ait. Balm of Gilead. (Fig. 268, 269). Branches terete, lvs. 

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

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

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

 growing wild, Can. and the Northern XT. S. Height 30 to 60f, with a pyramidal 

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

 .above. Sterile aments 2 to S' long, fertile 4 to 6. Buds flUed throughout with 

 fragrant resin. 



8 P. nigra L. ^. beTOlifolia Torr. Black Poplar. Towng branch^ pubes- 

 cent; lvs. deUoid-rhombic, conspicuously acuminate, finely crenate-serrate, smootih 

 both sides; aments without hairs. — Trees 30 to 40f high, planted at Hoboken, 

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



9 P. dilatata Ait. Lombabdt Poplar. Lvs. smooth, acuminate, deltoid, 

 serrate, the breadth equaling or exceeding the length ; irunh 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 nuisance. 

 t Italy 



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

 lobed and toothed, acuminate, dark green and smooth above, very white-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 Eur. 



Order CXXIII. SAURUEACEiE. SAnRURADs. 



Serbs with jointed stems, alternate, entire leaves furnished with stipules. Flow- 

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

 Ovaries 3 to 5, more or less tuited. Seeds ascending. Mmbryo enclosed in a sac 

 (amnios), outado of hard, meaiy albumen. Mg. 264. 



