PoPULus. SALICACE^. 217 



7. PopuLus CANDiOANS, Ait. Heart-kavcd Balsam Poplar. 



Branches terete ; leaves cordate, acuminate, serrate, whitish and reticulated underneath ; 

 petiole mostly hairy; ovary ovoid-globose; lobes of the stigma large and dilated. — Ait. 

 Kew. (ed. 1.) 3. p. 406 ; Michx. sylv. 2. t. 98._fig. 2; Pursh fl. 2. p. 618; Bigel. fl. Bost. 

 p. 370. 



Stem 40 - 50 feet high and 12-18 inches in diameter ; the bark smooth and greenish : 

 branches spreading and somewhat fastigiate. Leaves 4-6 inches long and of nearly the 

 same breadth, yellowish when young, but finally deep green above and whitish underneath : 

 petiole slender, a little compressed above. Sterile aments not seen. Fertile aments finally 

 6 inches or more in length ; the rachis and very short pedicels quite smooth. 



This poplar is said by Muhlenberg to grow in New- York, but I have not found it indigenous 

 within our limits. It has been seen, however, by Dr. Robbins and Mr. Oakes, in various 

 parts of Vermont, bordering on this Stale, and it doubtless grows on the western shores of 

 Lake Champlain. It is nearly allied to the common Balsam Poplar, but differs in its cordate 

 much larger leaves. The buds in both species are covered with an odoriferous adhesive 

 resin. 



Order ClII. BALSAMIFLU^. Blume. The Sweet-gum Tribe. 



Flowers monoecious, destitute of calyx and corolla, in aments which are furnished 

 with a caducous 4-leaved involucre. Sterile fl. in conical, sometimes com- 

 pound aments. Stamens numerous. Fertile fl. in globose amenta : ovaries 

 numerous, surrounded by small scales which finally become consolidated, 2- 

 celled, many-ovuled : styles 2, subulate or thick, stigmatose on one side. Cap- 

 sules immersed in the united scales, and forming a kind of globose strobile, 

 2-celled, 2-beaked, opening between the beaks. Seeds mostly abortive ; the 

 few fertile with a membranaceous margin. Albumen thin. Embryo straight, 

 with foliaceous cotyledons. — Trees, with alternate usually palmately lobed 

 leaves and deciduous stipules. 



1. LIQUID AMBAR. Linn. ; Endl. gen. 1902. swEET-avM. 



[From the Latin, liipiidum,, fluid, and amiar, amber; in allusion to the terebinthine fluid that exudes from the tree.J 

 Character same as that of the order. 



1. LiQuiDAMBAR STYRACiFLUA, Linu. Commov, Sweet-gum. Bilsted. 



Leaves with acuminate serrate lobes ; axils of the primary veins villous. — Linn. sp. (ed. 2.) 

 2. p. 418 ; Michx. Jl. 2. p. 202 ; Michx. f. sylv. 1. t. 62 ; Pursh, fl. 2. p. 635 ; Nutt. gen. 

 [Flora— Vol 2.] 28 



