396 



ARNICA 



ARONICUM 



thin, in a single, rarely double series. Native to Eu., 

 Asia, and N. Amer., about 10 species. Tincture of the 

 European .4. montana is used in medicine. Grown 

 mostly as alpines or in rockwork ; some species also grow 



well in the common 

 border. Prop, by divi- 

 sion, and rarely by seeds. 



A. Radical Ivs. cordate, 

 with slender or winged 

 petioles. 



cordifolia, Hook. Two 

 ft. or less high, hairy: 

 heads few or even soli- 

 tary, with inch - long 

 rays; involucre %in. 

 high, pubescent. Rocky 

 Mts. and W To be 

 grown as r.n alpine. 



latifolia, Bongard (A. 

 ventdrum, Greene). 

 Glabrous or very nearly 

 so. the st.-lvs. not cor- 

 date or petioled, the 

 radical Ivs. nearly round : 

 heads smaller than in 

 preceding. Rocky Mts. 

 andW. 



AA. Radical Ivs. not cor- 

 date, often petioled. 



amplexicaulis, Nutt. 

 Glabrous or nearly so: 

 Ivs. ovate to lance-ob- 

 long, acute, those on the 

 st. clasping and dentate: 

 st. leafy to the top. 

 Ore. and N. 



foliosa, Nutt. Pubes- 

 cent: Ivs. lanceolate, 

 strongly nerved, small- 

 toothed, the upper ones 

 somewhat clasping: 

 heads sometimes soli- 

 tary, short - peduncled : 

 6t. leafy, strict. Rocky Mts. and W. 



montana, Linn. MOUNTAIN TOBACCO. MOUNTAIN 

 SNUFF. Fig. 381. A foot high, the st. sparsely hairy: 

 radical Ivs. oblong-lanceolate, glabrous and entire: 

 heads 3-4, large. Eu. B.M. 1749. J.H. III. 34:441. 

 Gn. 24, p. 394. G. 29:215. The best known species 

 in cultivation and can be grown in the open border, 

 but none of the arnicas is common in American 

 gardens. 



A. CZus>i'=Doronicum Clusii. L. H. B. 



N. TAYLOR.f 



ARONIA (modification of Aria, a subgenus of the 

 allied genus Sorbus). Rosacese. CHOKEBERRY. Orna- 

 mental shrubs grown for their attractive white flowers 

 and for their handsome fruits, and also for the bright 

 autumnal tints of the foliage. 



Low plants: Ivs. deciduous, short-petioled, finely and 

 crenately serrate, glandular on the midrib above, con- 

 volute in bud: fls. in small corymbs, white; calyx 5- 

 lobed, petals 5, spreading; stamens numerous; ovary 

 6-celled, woolly at the top, with 5 styles united at the 

 base, the carpels connate but partly free on their ventral 

 suture: fr. a small pome, flesh without grit-cells, top 

 hemispherical. Three closely related species in E. X. 

 Amer. Closely related to Sorbus, which is easily dis- 

 tinguished by the sharply or doubly serrate, often pin- 

 nate Ivs. folded in bud and without glands above, by 

 the usually 2-3-celled ovary with the carpels' connate 

 on their ventral suture, otherwise often partly free, and 

 by the conical top of the fr. : quite distinct in general 



381. Arnica montana. 



appearance and habit and suggesting more an affinity 

 with Amelanchier. 



The aronias are small shrubs with simple deciduous 

 leaves turning bright red in autumn and with white 

 flowers in small corymbs followed by berry-like, red, 

 purple or black fruit. Well adapted for borders of shrub- 

 beries and quite hardy North. A. melanocarpa is hand- 

 somest in foliage and bloom, particularly the var. 

 grandifolia; its fruit ripens in August, but soon shrivels 

 and drops, while A. atropurpurea and A. arbulifolia have 

 showier and usually more numerous fruits; those of A. 

 atropurpurea ripen in early September and shrivel at 

 the beginning of the winter, while those of the last- 

 named species ripen later and remain plump and 

 bright far into the winter. 



They prefer moist situations, but A. melanocarpa 

 also grows well on drier and rocky soil. Propagation is 

 by seeds sown in fall or stratified; also by suckers and 

 layers, or by greenwood cuttings under glass. 



arbutiffilia, Spach (Sorbus arbulifolia. Heynh. Pyrus 

 arbulifolia, Linn. f. A. arbutifolia. Ell. A. pyrifolia, 

 Pers. Mespilus arbutifolia var. erylhrocdrpa, Michx.). 

 RED CHOKEBERRY. Upright shrub, 6-10 ft. high: Ivs. 

 short-petioled, oval to oblong or obovate, acute or 

 abruptly acuminate, crenately serrate, glabrous above 

 except some glands on the midrib, whitish or grayish 

 green and tomentose or pubescent beneath, 1 %-3 in. 

 long: corymbs tomentose, few- to many-fid., 1-1 Y-i in. 

 broad; fls. white or tinged red, ^-J^in. across: fr. sub- 

 globose or pear-shaped, bright or dull red, about J^in. 

 across. April. May. N. Y. to Minn., to Fla. and La. 

 B.M. 3668. G.F. 3:417. G.W. 5, p. 245. 



atrppurpftrea, Brit. (S6rbus arbutifolia var. atro- 

 purpurea, Schneid.). PURPLE CHOKEBERRY. Shrub, to 

 12 ft., closely allied to the last: Ivs. oblong to obovate, 

 grayish pubescent beneath, 2-3 J^ in. long; corymbs 

 tomentose, many-fld. : fr. ovoid to subglobose, purplish 

 black, about Jiin. high May, June. Nova Scotia 

 to Fla. 



melanocarpa, Spach (Sorbus melanocdrpa, Heynh. 

 Pyrus nlgra, Sarg. A. nlgra, Koehne. Pyrus arbuti- 

 folia var. nlgra, Willd.). BLACK CHOKEBERRY. Low 

 shrub, rarely to 6 ft.: Ivs. oval to obovate, abruptly 

 acuminate or obtuse, pale green and glabrous or nearly 

 so beneath: calyx and pedicels glabrous or nearly so: fr. 

 globose, about ^in. across, shining black. Nova Scotia 

 to Ont., south to Fla.. and Mich. April-June. B.B. 

 2:237. Var. grandifolia, Schneid. (Pyrus grandifolia, 



382. Aronia melanocarpa var. elata. (XJs) 



Lindl.). A taller, more vigorous shrub with larger, 

 obovate or broadly obovate lustrous Ivs. and larger fls. 

 in larger corymbs. B.R. 14:1154. Var elata, Rehd. 

 Fig. 382. Similar to the preceding, but Ivs. narrower, 

 generally oblong-obovate, acute. Var. subpubescens, 

 Schneid. Lvs. pubescent beneath when young. 



A.floribunda, Spach (Pyrus floribunda, Lindl.). Hybrid bet wpt n 

 A. arbutifolia and A. melanocarpa, similar to A. atropurpurea. but 

 usually more glabrescent. B.R. 12: 1006. G.W. 5, p. 246. It is of 

 garden origin and several forms of it are in cult. 



AR6NICUM: Doronicum. 



ALFRED REHDER. 



