Alnus.] LXX. BETULACE^. 461 



Tonse rivers. Generally fringes the banks of mountain-streams and rivers. Fl. 

 Sept.-Oct. Attains 80-90, and at times 100 ft., with a straight tall clear trunk, 

 generally 6-8, often 12, and at times 15 ft. girth. The largest trees are seen in 

 the basins of the Jhelam and Chenab. Bark brown, rough with dark furrows. 

 The wood is whitish, used for bedsteads ; the hooked sticks of rope bridges are 

 made of it. The twigs are tough, and are used for tying loads and in the con- 

 struction of twig bridges. The bark is used for dyeing and tanning. 



A. orientally ~D ne . ; DC. Prodr. xvi. ii. 185, somewhat resembles this species, 

 but differs by large short ovoid or subglobose fruit catkins, fruit without wing 

 or edge. Syria, Lebanon, Cyprus, Cilicia. 



The two sp. of this genus which are important for the forester in Europe are : 

 1. A. glutinosa, Linn. ; Hook. Stud. Fl. 346; Alder; Schwarzerle, German; 

 A une glutineux, French ; Ontanonero, It., with glabrous glutinous leaves. Europe, 

 North Africa, Cilicia, Asia Minor. Important as coppice- wood in deep marshes. 

 Wood soft, white when fresh cut, turning, on exposure to the air, into orange- 

 red, pale red when seasoned, the wood of knotty trees often beautifully mottled. 

 No heartwood. Weight 26-40 lb. Used for carving ; herring-barrels are made 

 of it. Lasts well under water. 2. A. incana, Willd. ; Weisserle, Germ. ; Aune 

 blanc, Fr. ; with pubescent leaves. North-East Europe, and mountains of 

 Central Europe, descending to the plains along the main rivers, and often cul- 

 tivated. Caucasus, Siberia, Amurland. Throws up abundantly root-suckers. 

 Both have distinctly tetrandrous flowers, 4 on the stalk of each scale, with 4- 

 lobed perianth, fruit with a narrow coriaceous edge. 



Order LXXI. SALICINEiE. 



Deciduous, fast-growing but not long-lived trees or shrubs, with scaly 

 buds. Wood soft, light, even-grained. Leaves alternate, simple, stipu- 

 late. Flowers dioicous in lateral catkins, which are similar in both 

 sexes, with spirally-arranged scales, each bearing one flower in its axil. 

 A glandular cup-shaped or irregularly-formed disc, in the male fl. with 

 two or more, generally free stamens ; in the female fl. with a 1 -celled 

 ovary, consisting of 2-4, generally 2, connate carpels which terminate in 

 as many short styles as there are carpels, numerous ovules on parietal 

 placentas adnate to the median line of the valves. Fruit a 1 -celled 2-4-, 

 generally 2-valved capsule dehiscing from the apex, the valves spreading 

 or rolling back. Seeds numerous, minute, with a mass of long silky 

 hairs on the funicle, which enclose the seed ; albumen none ; embrya 

 straight ; radicle inferior. Fruit catkins not persistent. 



Leaves short-petiolate ; scales entire ; stamens 2-12, generally 2, 



long exserted ; capsule 2-valved ...... 1. Salix. 



Leaves long-petiolate ; scales cut or jagged ; stamens 4-30 ; cap- 

 sule 2-4-valved 2. Populus. 



1. SALIX, Tournef. 



Leaves lanceolate ovate or elliptic, petioles short, generally less than 

 one-fourth the length of leaf. Stipules deciduous, larger and more per- 

 sistent on shoots and root-suckers. Scales of catkins deciduous or more or 



