ALNUS 



ALNUS 



47 



ALNUS (the ancient Latin name). Cupullferot, sub- 

 family Betulacece. ALDER. Trees or shrubs: Ivs. alter- 

 nate, shortly petioled, deciduous: fls. apetalous, monce- 

 cious in catkins, staminate ones elongated and pendu- 

 lous, pistillate ones erect, short, developing into an 

 ovoid, ligneous cone with persistent scales : fr. a 

 small nutlet. Twenty species in the northern hemi- 

 sphere, in America south to Peru. Hardy ornamental 

 trees and shrubs, suitable for planting on damp soil, 

 where they grow very rapidly, but A. cordata, firma, 

 Japonica, and also A.tinctoria prefer somewhat drier 

 soil. The profuse male catkins are pleasing in early 

 spring. The wood is valuable for its durability in water. 

 Usually prop, by seeds gathered in the fall and well 

 dried: sown in spring with but slight covering, and 

 kept moist and shady, they germinate soon ; a slight 

 covering with moss, taken off when the seedlings appear, 

 will be useful. At the end of the same year or the fol- 

 lowing springthe seedlings are transplanted, usually into 

 rows 1-2 ft. apart and 6 in. from each other. After two 

 years they can be planted where they are to stand. The 

 shrubby species, also A.glutinosa, grow from hardwood 

 cuttings placed in moist and sandy soil, also from layers, 

 and A. incana from suckers. Rarer kinds are grafted 

 on common potted stock in early spring in the propa- 

 gating house; grafting out-of-doors is rarely successful. 



Index: aurea, No. 10; cordata,5; cordifolia,5; denticu- 

 lata, 10; firma, Sieb. & Zucc., 2 and 4; glauca, 6; gluti- 

 nosa, 10; imperialis, 10; incana, 6; incisa, 10; Japonica, 

 4; laciniata, 6 and 10; maritima, 3; multinervis, 2 ; ob- 

 longata, 3 and 10 ; Oregana, 8 ; pyrifolia, 5 ; rubra, 8 ; 

 rubrinerva, 10 ; rugosa, 9 ; serrulata, 9 ; Sibirica, 1 ; 

 tiliacea, 5 ; tilice folia, 5 ; tinctoria, 7 ; viridis, 1. 



A. Fls. opening in the spring with the Ivs.; pistillate 



ones enclosed in buds during the winter: fr. with 

 broad membraneous wings. Alnobetula. 



1. viridis, DC. GREEN ALDER. Shrub, 3-6 ft. : Ivs. usu- 

 ally rounded at the base, round-ovate or oval, sharply 

 serrate, l%-4 in. long, pale green and pubescent on the 

 veins beneath: cones 3-4, oblong, slender peduncled. 

 Northern hemisphere, in the mountains, in different 

 varieties. Hardy low shrub with handsome foliage, of 

 very pleasant effect on rocky streamlets, with its long, 

 male catkins in spring. Var. Sibirica, Regel. (A. Si- 

 birica, Hort.). Sometimes tree, 25 ft.: Ivs. larger, cor- 

 date-ovate. 



2. firma, Sieb. & Zucc. Tree, to 30 ft.: Ivs. oblong- 

 lanceolate or ovate-lanceolate, sharply and doubly ser- 

 rate, with 10-15 pairs of veins, 2-4 in. long, often nearly 

 glabrous beneath : cones 2-4, peduncled. Japan. 



Var. multinervis, Regel. Lvs. with 14-24 pairs of 

 veins, thicker. Handsome tree with dark green Ivs., 

 growing on dry and rocky soil; quite hardy. 



AA. Fls. opening in the fall from catkins of the same 

 year: Ivs. not plicately folded in the bud. 



3. maritima, Nutt. (A. oblongdta, Regel., not Ait. nor 

 Willd.). Tree, to 30 ft. : Ivs. cuneate, oblong or obovate, 

 shining above, pale green beneath, glabrous, remotely 

 and crenately serrate, 1-4 in. long: cones 2-4, large, on 

 short, stout peduncles. Del., Md. S.S. 9:458. G.F. 

 4:269. Nutt. N. Am. S. 1: 10. Ornamental shrub or 

 small tree with handsome shining foliage, attractive in 

 autumn with its male catkins. 



AAA. Fls. opening in early spring before the Ivs., from 

 catkins formed the previous year and remaining 

 naked during the winter. 



B. Lvs. not plicate in the bud, green beneath, veins 



arcuate, ending mostly in the incisions: female 

 catkins usually solitary in the axils. 



4. Jap6nica, Sieb. & Zucc. ( A. firma, Hort., not S. & 

 Z.). Tree, 50-80 ft. : Ivs. cuneate, oblong-lanceolate, acu- 

 minate, sharply and irregularly serrulate, glabrous at 

 length, bearded in the axils of the veins beneath, 2-6 

 in. long : cones 3-6, peduncled. Japan. G.F. 6:345. 

 Tall, pyramidal tree with dark green foliage ; the 

 largest and perhaps the most beautiful of all Alders. 



5. cordata, Desf. (A. cordifblia, Ten. A. tiliacea, 

 Hort. ) . Small tree, 20-50 ft. : Ivs. cordate, ovate or round- 

 ish, acuminate, 2-4 in. long, bearded in the axils beneath, 



glandular when young : cones 1-3, peduncled. Italy, 

 Caucasus. L.B.C. 13:1231. G.C. II. 19: 285. Round- 

 headed tree with handsome, distinct foliage, changing 

 orange yellow in autumn, resembling that of a linden or 

 pear, therefore sometimes as A. tilice folia, or A. py- 

 rifblia, in gardens. Not quite hardy North. 



BB. Lvs. plicate in the bud, the veins going straight to 

 the points of the larger teeth: female catkins S-6 

 in every axil. 



c. Under side of Ivs. glaucous ; not bearded. 

 6. incana, Willd. Shrub or tree, to 60 ft. : branches pu- 

 bescent: Ivs. oval or oblong-ovate, acute, 1^-4 in. long, 



65. Alnus glutinosa (X 



doubly serrate, pubescent or nearly glabrous beneath: 

 cones 4-8, mostly sessile, %in. long. Northern hemi- 

 sphere, in different varieties. 



Var. glauca, Ait. ( A. glauca, Michx. ) . Shrub, to 12 ft. : 

 Ivs. often nearly glabrous beneath. N. Amer., Eu. 

 Em. 251. 



Var. vulgaris, Spach. Tree, to 50 ft. : Ivs. usually 

 densely pubescent beneath: cones 1 in. long. Eu., Asia. 



Var. pinnatifida, Spach. (var. laciniata, Hort.). Lvs. 

 pinnately lobed or cleft, with dentate lobes. 



7. tinctdria, Sargent (A. incana, var. tinctdria, Hort. ), 

 Tree, to 60 ft. ; Ivs. broadly ovate, 4-6 in. long, membra- 

 naceous, coarsely doubly serrate, slightly lobed, glau- 

 cous and rufously pubescent on the veins beneath. Ja- 

 pan. G.F. 10:473. Handsome ornamental tree of very 

 vigorous growth, with large foliage. 



8. rubra, Bong. (A. Oregana, Nutt.). Tree, 40-50 ft. : 

 Ivs. oblong-ovate, 3-5 in. long, crenate-serrate, slightly- 

 lobed, revolute on the margin, nearly glabrous beneath; 

 petioles and veins orange colored:' cones 6-8, oblong. 

 W. N. Amer. S.S. 9:45*. Nutt. N. Amer. S. 1: 9. 



CO. Under side of Ivs. green or brownish green; usually 

 bearded. 



9. rugdsa, Spreng. (A. serrulata, Willd.). Shrub, to 25- 

 ft. : Ivs. usually cuneate, obovate or elliptic, acute or 

 rounded at the apex, 2-5 in. long, finely serrate, usually 

 pubescent on the veins beneath: cones short-stalked. 

 E. N. Amer., from Mass, south. Em. 248. 



10. glutindsa, Gaertn. BLACK ALDER. Fig. 65. Tree, to- 

 70 ft. : Ivs. orbicular or obovate, rounded or emarginate 

 at the apex, 2-5 in. long, irregularly obtusely serrate, 

 with 5-7 pairs of veins, nearly glabrous beneath, glu- 

 tinous when unfolding : cones distinctly peduncled. 

 Eu., N. Afr., Asia, naturalized in some localities in N. 

 Amer. A vigorously growing tree with dark green ^ 

 dull foliage, valuable for planting in damp situations. 

 Commonly planted in many forms : Var. aurea, Versch. 

 Lvs. yellow. 1. H. 13:490. Var. denticulata, Ledeb. 

 (A. oblongdta, Willd.). Lvs. usually cuneate, serrulate- 



