252 



ALNUS 



ALNUS 



Usually propagation is 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 spring, the seedlings are transplanted, usually 

 into rows 1 to 2 feet apart and 6 inches from each other. 

 After two years, they may 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 propagating-house; grafting out-of- 

 doors is rarely successful. 



164. Alnus japonic*. 

 (XJfl 



INDEX. 



Alnobetula, 1. 

 aurea, 12. 

 barbata, 12. 

 communiK, 12. 

 cordata, 7. 

 cordifolia, 7. 

 denticulata, 12. 

 firma, 3, 4, 6. 

 glauca, 8. 

 plutinosa, 12. 

 imperialis, 12. 

 incana, 8, 9. 



incisa, 12. 



iaponica, 6. 

 aciniata, 8, 12. 

 maritima, 5. 

 Mitchelliana, 2. 

 oblonoata, 5, 12. 

 oregnna, 10. 

 oxyacanthifolia, 12. 

 pendula, 4. 

 pinnatifida, 8. 

 pyrifolin. 7. 

 rotundifolia, 12. 



rubra, 10. 

 rubrinervia, 12. 

 rugosa, 11. 

 serrulata. 11. 



tlli'lr "1. 7. 



tilixfolia, 7. 

 tinctoria, 9. 

 undviUtta, 1. 

 viridis, 1, 2. 

 vulgaris, 8, 12. 

 yasha, 3. 



A. Pistillate calkins terminal, inclosed during the winter 

 in the bud, opening in spring: jr. with broad mem- 

 branous wing: winter-buds sessile with 2 or more 

 unequal scales. (Alnobetula.) 

 B. Lvs. ovate or elliptic, with 5-10 pairs of veins. 



1. viridis, DC. (A. Alnobetula, Hartig. A. undulata, 

 Willd.). EUROPEAN GREEN AIDER. Shrub, 2-6 ft. : Ivs. 

 elliptic or ovate, to round-ovate, acute, usually nar- 

 rowed at the base, sharply serrulate, \-1Yi in. long, 

 glutinous while young, bright green above, pale green 

 and glabrous beneath or pubescent on the veins: stam- 

 inate catkins 2-3J^ in. long; pistillate catkins with 

 glabrous or puberulous peduncles: cones 3-4, oblong, 



slender-peduncled. March, April. Mts. of Eu. L.B.C. 

 12:1141. H.W. 2:14. 



2. Mitchelliana, Curt. (A. viridis of most American 

 authors). AMERICAN GREEN ALDER. Shrub, 2-10 ft.: 

 young branchlets glabrous or sparingly pubescent: Ivs. 

 elliptic or ovate-elliptic, acute or obtuse, rounded or 

 subcordate at the base, 1 J^-3 in. long, densely serrulate, 

 glutinous while young, with impressed veins above, 

 reticulate beneath and glabrous: staminate catkins 2-3 

 in. long; pistillate catkins with pubescent peduncles: 

 cones 3-6, oblong, slender-peduncled. March, Apr. 

 Mts. of N. E. Amer., west to Brit. Col., south to N. C. 

 Hardy shrub with handsome bright green foliage, 

 very aromatic when unfolding and of very pleasant 

 effect in spring with its long male catkins; handsomer 

 than the preceding species. 



BB. Lvs. ovate-oblong to ovate-lanceolate, with 

 pairs of veins. 



3. yfisha, Matsum. (A. firma var. ydsha, Winkl.). 

 Tree, to 30 ft.: young branchlets pubescent: Ivs. ovate- 

 oblong, 2-4 in. long, acute, usually rounded at the base, 

 sharply and irregularly serrate, with 12-18 pairs of 

 veins, pubescent on the veins beneath: cones 1-3, ellip- 

 soid or sub-globose, %in. long, on slender peduncles 

 about 1 in. long. Japan. J.C.T. 16:2. 



4. pendula, Matsum. (A. firma var. multinervis, 

 Regel). Tree, to 30 ft., or shrub: young branchlets 

 pubescent: Ivs. oblong-lanceolate, acute or acuminate, 

 2-4 in. long, irregularly and often nearly doubly ser- 

 rate, with 18-24 pairs of veins, pubescent on the veins 

 beneath, at maturity nearly glabrous: cones 3-5, 

 ovoid, about H m - long, in pendulous racemes, 1-2 in. 

 long. Japan. S.I.F. 2:12. J.C.T. 16:3. Very hand- 

 some alder, still rare in cult.; the plant cult, under this 

 name is usually the preceding species. 



AA. Pistillate catkins axillary, appearing in autumn: 

 winter-buds with 2 equal scales, stalked. (Gym- 

 nothyrsus.) 



B. F Is. opening in the fall from catkins of the same year: 



Ivs. not plicately folded in the bud. 



5. maritima, Nutt. (A. oblongata, Regel, not 

 Ait. nor Willd.). Tree, to 30 ft.: Ivs. cuneate, 

 oblong or obovate, shining above, pale green 

 beneath,' glabrous, remotely and crenately ser- 

 rate, 2-4 in. long: cones 2-4, large, on short, stout 

 peduncles. Del., Md. S.S. 9:458. G.F. 4:269. 

 Nutt., N. Amer. S. 1 : 10. Ornamental shrub or small 

 tree with handsome shining foliage, attractive in 

 autumn with its male catkins. 



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

 catkins formed the previous year and remaining 

 naked during the winter. 



C. Lvs. not plicate in the bud, green beneath, veins arch- 



ing: cones 1-6, long-stalked. 



6. japonica, Sieb. & Zucc. (A. firma, Hort., not Sieb. & 

 Zucc.). Fig. 164. Tree, 50-80 ft. : Ivs. cuneate, oblong- 

 lanceolate, acuminate, 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 (adapted in Fig. 164). S.I.F. 1:19. TalL 

 pyramidal tree with dark green foliage; the largest and 

 perhaps the most beautiful of all alders. 



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

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

 roundish, acuminate, 2-4 in. long, bearded in the axils 

 beneath, glandular when young: cones 1-3, ovoid, 

 about 1 in. long, peduncled; nutlets with narrow wing. 

 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 called A. tilixfolia 

 or A. pyrifblia, in gardens. Not quite hardy N. 



