SORBUS 



SORBUS 



3195 



c. Habit tree- like 7. hybrids 



cc. Habit shrub-like 8. spuria 



A A. Foliage simple. 



B. Fr. with persistent calyx. 



c. Under side of Its. glabrous at 

 length, green: Its. lobed: ovary 

 inferior: fr. brown, with grit- 

 cells 9. torminalis 



cc. L'nder side of hs. grayish or 

 whitish tomentose: ovary half- 

 superior. 



D. Lts. lobed or sharply serrate. 

 E. Shape of hs. orate to oblong, 



usually acute. 

 F. Margin of hs. lobed. 



G. Base of the usually 

 broadly ovate hs. most- 

 ly rounded 10. latifolia 



GG. Base of the ovate to 

 oblong-ovate Ivs. 



broadly cuneate 11. intermedia 



FT. Margin of hs. sharply and 



doubly serrate 12. Aria 



EE. Shape of hs. suborbicular to 



broadly obovate 13. umbellata 



DD. Lrs. serrulate, grayish-tomen- 

 tose or sometimes glabrescent 



beneath 14. alpina 



BB. Fr. with deciduous calyx having a 



circular scar: ovary quite inferior. 

 c. L'nder side of hs. glabrous or 



slightly pubescent. 

 D. Styles usually 2: hs. ovate to 



elliptic-ovate 15. alnifolia 



DD. Styles usually 5: hs. elliptic- 

 oblong to obovate-oblong 16. caloneura 



cc. Under side ofhs. white-tomentose . 17. Folgneri 



Group 1. AUCTJPARIA. 



1. americana, Marsh. (Pyrus americana, DC. S. 

 micrdntha, Dum.-Cours.). AMERICAN MOUNTAIX-ASH. 

 DOGBERRY. Fig. 3648. Small tree, attaining 30 ft., with 

 spreading branches, or sometimes shrubby: Ifts. 11-17, 

 lanceolate, long-acuminate, sharply serrate, glabrous or 

 slightly pubescent when young, light green above, paler 

 beneath, l%-4 in. long: fls. K-J4 m - across, in dense, 

 3-6-in.-broad, usually glabrous corymbs: fr. globose, 

 bright red, H-J^in. across, with the calyx-lobes very 

 small and connivent. May, June. Newfoundland to 

 Man., south to Mich, and N. C. S.S. 4:171, 172. F.E. 

 23:209; 32:721. Var. microcarpa, Torr. & Gray (S. 

 microcdrpa, Pursh) , has narrower foliage and very small 

 frs. about Kin. across. 



2. decora, Schneid. (S. americana var. decora, Sarg. 

 Pyrus sambudfolia, Gray, not Cham. & Schlecht. 

 Pyrus sitchensis, Rob. & Fern., not Piper. S. scopulina, 

 Brit., not Greene). Small tree or shrub, closely allied to 

 the preceding: Ifts. 7-15, oval to ovate-lanceolate, or 

 oblong, obtuse to short-acuminate, serrate, glabrous and 



3648. Sorbus americana. ( X M) 



dark green above, rather pale and usually pubescent 

 beneath when young, or glabrous, 1^-3 in. long: fls. 

 J4-Hin- across, in 2-4-in.-broad and rather loose 

 corymbs, sometimes few-fld.: fr. globose, ovoid when 

 young, red, about J^in. across, with more or less upright 

 calyx-lobes. May. Labrador to Minn., south to N. Y. 

 and Vt. S.S. 4:173, 174. Often confounded with the 

 preceding species; intermediate forms are not uncom- 

 mon in regions where the two meet. Both are very 

 handsome in autumn with their large clusters of bright 

 red fr. and particularly S. decora is often planted for its 

 showy fr. 



3. Aucuparia, Linn. (Pyrus Aucuparia, Gaertn.). 

 EUROPEAN MOUNTAIN-ASH. ROWAN TREE. Fig. 3649. 

 Round-headed tree, 2040, occasionally 60 ft. high: 

 young branchlets pubescent, grayish brown when older: 

 petioles more or less tomentose; Ifts. 9-15, oblong to 

 oblong-lanceolate, serrate, entire toward the base, dull 

 green above, pubescent beneath or rarely glabrous, %-2 

 in. long: fls. white, K m - across, in flat, 4-6-in.-broad, 

 tomentose or sometimes almost glabrous corymbs; sta- 

 mens about as long as petals: fr. globose, about ^in. 

 across, bright red. May, June % Eu. to W. Asia and 

 Siberia. H.W. 3:54, pp. 78, 79. Var. dulcis, Kraetzl 

 {var. moravica, Zengerling). Almost glabrous: petioles 

 purplish; Ifts. oblong-lanceolate, 2-3 in. long, glauces- 

 cent beneath, usually serrate only above the middle. The 

 frs. are of an agreeable acid flavor and recommended 

 for preserves. The tree thrives well in cold northern 

 climates where hardly any other fr.-tree will grow. 

 G.M. 52:887. Var. rossica, Spaeth, is similar and also 

 bears edible fr., but the Ifts. are larger and broader and 

 more serrate. Var. Beissneri, Rehd. (var. dulcis 

 laciniata, Beissn., not var. laciniata, Hartm.), is a hand- 

 some and graceful form of var. dulcis with the Ifts. pin- 

 nately lobed and the If.-stalks and young branchlets 

 bright red. G.W. 3:267. Var. fastigiata, Loud., forms 

 a narrow pyramidal tree, with upright branches. Var. 

 pendula, Hort., has long and slender pendulous branches. 

 M.D. 1911, p. 246. Var. integerrima, Lange. Lfts. 

 entire or nearly so. Var. Fifeana, Dipp. (var. fructu- 

 luteo, Hort.). Fr. yellow. There are also varieties with 



