ROSACEAE (rose FAMILY) 459 



O-10-) fruited ; fruit larger, 8-10 mm. in diameter, cJaret-colored to pitrplish- 

 black. (Aronia Britton.) — Similar habitats, centr. Me., southw. and westw. ; 

 common. 



8. P. melanocarpa (Michx.) Willd. Shrub, similar in habit, generally of 

 lower stature ; leaves varj-ing from rather broadly oblong and acuminate to 

 spatulate-oblanceolate and scarcely pointed, glabrous or early glahrate beneath 

 as well as above ; pedicels and calyx also nearly or quite smooth ; fruit vei-y dark 

 purple or essentially black. (Aronia nigra Britton.) — Moist woods, but also 

 rocky uplands ; common northw. and extending southw. in the Alleghenies at 

 least to N. C. 



The members of this section occasionally form natural hybrids with those of 

 § 4. These may be recognized usually by their imperfectly pinnate or pinnatilid 

 leaves. 



§4. S6RBUS (L.) S.F.Gray. (Mountain Ash.) Leaves odd-pinnate, icith 

 rather numerous leaflets; cymes compouiid; styles distinct ; pome berry- 

 like, small. Trees or tall shrubs. Sorbcs [Tourn.] L. 



9. P. americana (Marsh.) DC. (American M.) Nearly glabrous or soon 

 becoming so ; leaflets 13-15, lanceolate, taper-pointed, sharply serrate with 

 pointed teeth, bright green ; cymes large and flat ; berries globose, bright red, 

 not larger than peas. {Sorbus Marsh.) — Woods, Lab. to Man., s. to n. and 

 w. X. E., N. Y., the Great L. region, and in the mts. to X. C. ; common. 



10. P. sitchensis (Eoem.) Piper. Xearly glabrous; leaflets oblong, oval, 

 or lance-ovate, mostly obtuse or abruptly pointed, serrate (often doubly) 

 with more spreading teeth, rather pale beneath, of firmer texture than in the 

 preceding; flowers (earlier) somewhat larger (8-11 mm. broad); fruit 8-10 

 mm. in diameter. (P. sambucifolia Man. ed. 6, not C. & S. ; Sorbus Eoem.) — 

 River-banks and damp rocky uplands, Lab. to centr. Me., westw. and north- 

 westw. to the Pacific. 



11. P. AcccpAria (L.) Ehrh. (European M., Powan Tree.) Leaflets 

 narrowly oblong, mostly obtuse, rather pale beneath, always more or \e&s pubes- 

 cent or tomentose at least on the lower surface. (Sorbus L.) — Extensively 

 cultivated for ornament, and now tending to become naturalized. (Introd. 

 from Eu. ) 



7. AMELANCHIER Medic. Juneberrt 



Calyx 5-cleft. Petals obovate to oblong, rarely linear. Stamens numerous, 

 short. Styles 5, united below. Ovary 5-celled, each ceil 2-ovuled, but with a 

 projection growing from the back of each and forming a false cartilaginous 

 partition, the sweet and edible berry-like pome thus 10-celled, with one seed 

 in each cell (when all ripen). — Small trees or shrubs, with simple leaves, 

 and white racemose flowers. (Xame said to be barbaric, the derivation not 

 satisfactorily explained.) 



Petals narrowly oblong, 14—25 mm. in length ; early flowering; leaves finely 



and sharply serrate " 1. A. canadeji»i)<. 



Petals oblong to obovate. 4-12 mm. in length. 

 Flowers racemed; racemes normally 5-x -flowered: leaves (at first folded 

 lengthwise) mostly obtuse, sometimes even cordate at base. 

 Flowering early (mostly 1 Apr.-15 May, fruit ripe June-July); leaves 



oblong or suborbicular-oblong, finely serrate . . " . . 2. A. ohlongifolin. 



Flowering later (mostly 15 May-2.o June, fruit ripe Aug.-Sept.); leaves 



suborbicular-oblong. coarsely dentate Z. A, spicata. 



Flowers soHtary or 2-4 in terminal fascicles ; leaves (flat even in verj' early 



stages) acutish or subcuneate at base ' . ". 4. A. oligocnrpa. 



1. A. canadensis (L.) Medic. (Shad Bush. Service Berry.) Tree or 

 shrub, 3-12 m. high, nearly or soon glabrous; leaves (when young folded 

 lengthwise and brownish-purple) ovate to ovate-oblong, usually somewhat cor- 

 date at base, pointed, finely and sharply serrate, 4-0 cm. long. .3-fi cm. \\ide ; 

 bracts and stipules very long-silky-ciliate ; flowers large, in drooping racen^es; 



