WILLOW FAMILY 



8. Populus nigra I,. Black Poplar. 

 (Fig. 1171.) 



\ilns nigra L. Sp. PI. 1034. 1753. 

 A large tree, sometimes 100 tall and the trunk 

 in diameter, usually much smaller. Twigs te- 

 ete; young foliage somewhat pubescent, the ma- 

 re leaves firm, nearly or quite glabrous; petioles 

 ender, flattened laterally; leaves broadly deltoid, 

 aptly acuminate at the apex, broadly cuneate or 

 se at the base, crenate, 2 / -4 / long; staminate 

 aents i'-2 / long; stamens about 20; pistillate 

 icnts -2'-$' long in fruit, spreading; capsule ob- 

 ng, very obtuse, borne on pedicels of much less 

 an their own length. 



Valleys of the Hudson and Delaware Rivers, natu- 

 ilized from Europe. April-May. 



The Lombardy Poplar, Populus dilatala, commonly 

 'anted for ornament, occasionally spreads by sending 

 i shoots from its subterranean parts. 



493 



Populus deltoides Marsh. Cottomvood. Necklace Poplar. (Fig. 1172.) 



Populus del I, >iiics Marsh. Arb. Am. 106. 1785. 

 Populus Carolinensia Mm-m-h, \\T/ I'l M 1785. 

 Populus mnnilifera Ait. Hurt. Krw. 3: \<f>. 1789. 

 Pxpnlus angulata Ait. Hort. Kew. 3: 4.17. 1789. 



A large tree, the greatest of the poplars, attain- 

 ing a maximum height of 150 and a trunk diam- 

 eter of 7 ',4, the bark grayish -green, somewhat 

 rough when old. Foliage glabrous; leaves broadly 

 deltoid-ovate, abruptly acuminate at the apex, cren- 

 ulate, truncate at the base, 4 / -/ / long; petiole flat- 

 tened laterally, stout, about as long as the blade; 

 bracts glabrous, deeply fimbriatc; staminate anicnts 

 drooping, 3 / -5 / long, 5 "-6" in diameter; pistillate 

 aments loosely flowered, becoming 6'-io / long in 

 fruit; capsule ovoid, acute, 4"-5" long, 2-4-valved, 

 shorter than or equalling their pedicels. 



In moist soil, especially along' streams and lakes, 

 Quebec to the Northwest Territory, south to New Jer- 

 sey, Florida, Colorado and New M< \io.. \Vmxl -..ft, 

 weak, dark brown; weight per cubic foot 24 Ibs. 

 April-May. Also called Carolina Poplar. 



2. SALIX L. Sp. PI. 1015. 1753. 



Trees or shrubs, with single-scaled buds, the scales with an adherent membrane within, 

 mostly narrow and short-petioled leaves and persistent or early deciduous broad or minute 

 stipules. Bracts of the aments entire. Disk gland like, small or minute. Staminate aments 

 dense, erect, spreading or drooping. Staminate flowers with i-io, mostly 2, stamens, their 

 filaments distinct or sometimes united. Pistillate aments usually erect or spreading. Ovary 

 sessile or short-stipitate. Style short or filiform. Stigmas 2, entire or 2-cleft. Capsule 

 mostly 2-valved. [Name ancient.] 



About 160 species, of wide geographic distribution throughout the north temperate and arctic 

 zones, a few in the southern hemisphere. Besides the following, some 45 others occur in the 

 northern and western parts of North America. 



=i: Filaments pubescent, at least toward the base; stamens more than a (3-7). 

 No glands on petioles or stipules. 



Capsule ovoid, about twice as long as its pedicel, 

 leaves short-petioled, lanceolate. 



Leaves narrowly lanceolate, green on both sides. 

 Leaves lanceolate, silvery-white beneath. 

 Leaves slender-petioled, broadly lanceolate. 

 Capsule long-conic, much longer than its pedicel. 

 Petioles and stipules prominently glandular. 



** Filaments pubescent; stamens only a. 

 Trees, cultivated and naturalized or adventive. 



I. S. n: 



a. S. Wardi. 



3. S. amygdaloides. 

 5. S. fragilis. 



4. 5. li< 



