246 Karl M. Wiegand and Arthur J. Eames 



1. S. americana Marsh. (Pirns americana of Cayuga Fl. Pynts amcricana of Gray's 



Man., ed. 7.) American Mountain Ash. 

 Boggy and springy places, apparently only in limy soils; rare. June. 

 Michigan Hollow Swamp (D.) ; around Woodwardia Bog (D.) ; Malloryville 

 Bog (D.) ; McLean Bogs (DA); Beaver Brook. 

 Lab. to Man., southw. to n. and w. N. E., N. Y., and Mich., and in the mts. to N. C. 



2. S. dumosa Greene. (See Rhodora 23:266. 1921. Pyrus sitchensis of Gray's Man., 



ed. 7. Pirns sambucifolia of Cayuga Fl., at least in part.) 

 Roadsides and the borders of woods, in gravelly or stony light neutral soils; rare. 



May 25-June 20. 

 Doubtfully native: swamp in Enfield (/. P. Young); by road and woods n. of 



Caroline Center, frequent; by road near Freeville, 1882 (D. in C. U. Herb.). 

 Native: Lab. to Alaska (?), southw. to cent. Me., Pa., Mich., and Colo. 



3. S. Aucuparia L. (Pirns sambucifolia of Cayuga Fl., at least in part.) European 



Mountain Ash. Rowan Tree. 

 Occasionally escaping from cultivation to roadsides and thickets, as w. of Michigan 

 Hollow Swamp and at Kidders. 

 Native of Eu. 



9. Aronia Medic. 



a. Leaves and corymbs tomentose; fruit purple. 1. A. arbutifolia, 



var. atropurpurea 

 a. Leaves and corymbs glabrous ; fruit practically black. 2. A. melanocarpa 



1. A. arbutifolia (L.) Ell, var. atropurpurea (Britton) Schneider. (Pirus arbuti- 



folia, var. erythrocarpa, of Cayuga Fl. Pyrus arbutifolia, var. atropurpurea, of 



Gray's Man., ed. 7.) Red Chokeberry. 



Bogs; scarce. June. The flowers and fruit mature later than in A. melanocarpa. 



Headwaters Swamp ; s. slope of Connecticut Hill ; Michigan Hollow Swamp ; 



South Hill Marsh (D. !) ; Slaterville Swamp; Junius ponds. Dudley cites a station. 



" South Hill, near the R. R., on the rocky bank of the South Quarry Cr.," but this 



would be a very unusual habitat. 



Newf. to Ont. and Mich., southw. possibly to Fla. ; common on the Coastal Plain. 



2. A. melanocarpa (Michx.) Britton. (Pirns arbutifolia, var. melanocarpa, of 



Cayuga Fl. Pyrus melanocarpa of Gray's Man., ed. 7.) Black Chokeberry. 



Acid peat bogs and in marly bogs ; common. Mav 20-June 15. 



Enfield (D.) ; Danby (D.) ; Larch Meadow (D.j ; South Hill Marsh; Slaterville 

 Swamp; McLean Bogs (D.l) ; Freeville; Junius peat bogs, and also marly moor 

 of Lowery Ponds ; Spring Lake ; and elsewhere. Stations in limy soils are infrequent. 



N. S. to Mich., southw. to Fla. ; common on the Coastal Plain. 



10. Amelanchier Medic.- 



a. Leaves coarsely toothed, not acuminate ; hypanthium prominent and cup-shaped on 

 the young fruit ; sepals revolute ; summit of ovary woolly ; shrubs. 

 b. Leaves oval, with straight veins and prominent teeth; petals 11-22 mm. long; 

 plant 1-3 m. high. 

 c. Petals 11-15 mm. long; lower pedicels 7-20 mm. long; calyx 3.5-6 mm. in 

 diam. to curve of sepals, the sepals 2-3 mm. long ; anthers 0.6-0.8 mm. long ; 

 leaves green, usually with some persistent wool beneath ; plant somewhat 

 stoloniferous, usually in large clump-like colonies. 1. A. sanguinea 



20 For recent changes in nomenclature and treatment, see Rhodora 14 : 117 (1912), also 22 : 146 

 (1920). and 23 : 48 (1921). 

 The species of this genus are commonly called Shadbush, June Berry, or Service-berry. ■ 



