WILLOW FAMILY. 491 



Populus balsamifera L,. Tacamahac. 



Balsam Poplar. (Fig. 1165.) 

 f>ii/its balsamifera L. Sp. PI. 1034. ^753. 

 A large tree, with nearly smooth gray bark, reach- 

 a maximum height of about 80 and a trunk 

 jmeter of 7, the branches stout, spreading, the 

 je buds very resinous, the foliage glabrous, 

 ives broadly ovate, dark green and shining 

 ave, pale beneath, acute or acuminate at the 

 ?x, rounded or subcordatc at the base, crenulate, 

 -5' long, petioles terete; aments and bracts somc- 

 jat pubescent; stamens 18-30; lobes of the stigmas 



ad; capsule ovoid, 2-valved, short-pedicelled. 

 In moist or dry soil, especially along streams and 

 \\wfoundlandtoHudspn Bay and Alaska, south 

 Maine, New York, Michigan, Idaho and British 

 .ilumbia. Wood soft, weak, brown, compact; weight 

 cubic foot 23 Ibs. April. 



Populus balsamifera candicans (Ait.) A. Gray, Man. 



Ed. 2, 419. 1856. BALM OF GILEAD. 

 bpulns candicans Ait. Hort. Kew. 3: 406. 1789. 



Leaves broader, cordate at the base; petioles usually pubescent. New Brunswick to New Jer 

 ,-, west to Minnesota, mostly escaped from cultivation, apparently indigenous imrtliwuid. 



Populus angustifolia James. Narrow-leaved Cottomvood. (Fig. 1166.) 



is angnsti/olia James, I.ong's l;xp. i: 497. i85- 

 Pofiulus baisatnifi-ni var. angns/i/i'/iii S Wats. Bot. 

 King's Kxp. 327. 1871. 



A slender tree, maximum height about 65, trunk 

 diameter 2; crown narrowly pyramidal, branches as- 

 cending, foliage glabrous. Twigs terete, gray; leaves 

 lanceolate, ovate-lanceolate or ovate, spreading, dry- 

 ing brownish, gradually acuminate or acute at the 

 apex or some of them obtuse, narrowed, rounded or 

 rarely subcordate at the base, 2 / ~4> / long, %'-l%' 

 wide, finely crenulate from base to apex; petioles 

 plano-convex, not flattened laterally; X'->j' long; 

 lateral veins 8-15 on each side of the blade; stami- 

 nate aments oblong-cylindric, i'-2#' long; lobes of 

 the stigmas broad; capsules ovoid, short-pedicelled. 



In moist soil, i-spi-dally along sir- -anis, Northwest Ter- 

 ritory to Dakota, Nebraska. Ni w M> \ii-o. and Ari/ona. 

 Wood soft. weak, brown, compact; weight per cubic foot 

 24 Ibs. April-May. 



4. Populus acuminata Rydberg. Black 

 Cottonwood. (Fig. 1167.) 



Populus acuminaia Rydberg, Bull. Torr. Club, 20: 50. 



i893- 



A slender tree, with terete twigs, reaching ap- 

 proximately the dimensions of the preceding spe- 

 cies, the crown broadly pyramidal with spreading 

 branches, the foliage glabrous. Leaves rhomboid- 

 lanceolate, spreading or drooping, drying green, 

 abruptly or gradually long-acuminate at the apex, 

 cuneate, obtuse or rounded at the base, 2 / -6 / long, 

 i'-2%' wide, crenulate or the base entire; petioles 

 slender, i / -2^ / long; staminate aments about \ l /i r 

 long; pistillate aments slender, drooping, 3'-s' 

 long; capsules ovoid, obtuse, distinctly pedicelled. 



Range apparently nearly that of the preceding 

 species. April-May. 



