224 ROSACEiE. Pyrtts. 



§ 2. Adenorachis, DC. (Aronia, Pers. partly.) Leaves simple ; the midrib glandular along the 

 upper side : cymes compound : petals spreading, concave : styles 3-5, united at the base : 

 pome {small) turbinate or globose : carpels somewhat cartilaginous. 



2. Pyrus arbutifolia, Linn.f. Choke-berry. 



Leaves obovate-oblong, obtuse, acute or acuminate, crenately serrulate, attenuate into a 

 short petiole, somewhat shining above ; fruit pyriform or nearly globose. — Linn.f. suppl, 

 p. 256 ; Hook.fl. Bor.-Am. \.p. 204 ; Beck, hot. p. 114 ; Darlingt.fl. Cest.p. 296 ; Twr. 

 4* Gr. fl. N. Am. 1. p. 471. Aronia arbutifolia, Torr. fl. 1. p. 476. 



var. 1 . erythrocarpa : calyx, peduncles and lower surface of the leaves, at least when 

 young, tomentose ; fruit dark red. Hook. I. c. ; Torr. 4- Gr. I. c. P. arbutifolia, Willd. sp. 

 2. p. 1012 ; Pursh, fl. 1. p. 339 ; Bigel. fl. Bost. p. 195 ; DC. prodr. 2. p. 637. P. flori- 

 bunda, Lindl. bat. reg. t. 1006. Mespilus arbutifolia, Linn. sp. 1. p. 478 ; Michx. fl. 1. 

 p. 292 (var. erythrocarpa). Aronia pyrifolia and arbutifoHa, Pers. syn. 2. p. 39. A. arbuti- 

 folia. Ell. sk. 1. p. 556. 



var. 2. melanocarpa : calyx, peduncles and leaves smooth, or nearly so ; fruit purplish- 

 black. Hook. I. c; Torr. ^ Gr. I. c. P. melanocarpa, Willd. enum. l.p. 525; DC. I. c. 

 P. grandifolia, Lindl. hot. reg. t. 1154. Mespilus arbutifolia, var. melanocarpa, Michx. I. c. 

 Aronia melanocarpa, Ell. I. c. A. arbutifoHa, var. melanocarpa, Torr. I. c. 



A shrub 2-3 feet high, with slender branches. Leaves 1-2 inches long, sometimes 

 obtuse or even emarginate, but commonly acute and with a slight acumination, bright green 

 above, pale underneath, and the midrib with one or two rows of dark purple glands ; the 

 margin finely serrate, with the points of the teeth much inflexed. Corymbs numerous, 

 10 - 20-flowered. Flowers white. Fruit the size of a large whortleberry, sweetish, but 

 astringent. 



Thickets and woods, in both wet and dry situations ; common. Fl. May - June. Fr. 

 August — September. The Red and Black Chokeherries are certainly varieties of one species. 

 The former sometimes occurs with the leaves smooth, and the calyx only slightly pubescent. 



§ 3. SoRBVs, Linn. Leaves pinnate or pinnately lobed : cymes compound: petals spreading, flat ; 

 styles 2-5, distinct : pome {small) globose or turbinate : carpels not cartilaginous. 



3. Pyrus Americana, DC. Mountain Ash 



Leaves pinnate, smooth ; leaflets oblong-lanceolate, acuminate, sharply serrate with mucro^ 

 nate teeth ; cymes large ; fruit (bright red or scarlet) compound. — DC. prodr. 2. p. 637 

 Hook. fl. Bor.-Am. 1. p. 204 ; Torr. <^ Gr.fl. N. Am. l.p. 472 ; Wats, dendrol. Brit. t. 54, 

 Sorbus Americana, Willd. enum. l.p. 520 ; Pursh,fl. l.p. 341 ; Torr.fl. 1. p. 477; Bigel. 

 fl. Bost. p. 194. S. aucuparia, var. Americana, Michx. fl. I. p. 290. 



A shrub or small tree, 10 - 25 feet high, and sometimes 4-6 inches in diameter, with a 

 smooth bark. Leaves 8-12 inches or more in length : leaflets 6-8 pairs, 2-3 inches 



