53. ROSAGEAE 121 



3. Young leaves densely white-tomentose; dwarf colonial shrubs 

 0.5-1.5 m tall; rocky or sandy soil; in the northern and west- 

 ern counties, s. to Mercer and Will counties. May. Low 



Shadbush. [A. huynilis Wieg. ; A. stolonijera Wieg.] 



A. spicata (Lam.) K.Koch 



14. Cydonia Mill. - Quince 

 C. oblonga Mill. Fully established on Atwood Ridge, Union Co.; 

 native of Asia. May. 



15. Sorbus L. — Mountain-ash 



1. Winter-buds densely whitish-villous, 5-10 nun long; leaflets 



elliptical, acute, 3-5 cm long; flowers 8-9 mm broad; fruits 9- 



1 1 mm in diameter ; native of Eur. ; cultivated, and occasionally 



escaping to woods or roadsides. European Mountain-ash. Often 



mistaken for the following species S. aucuparia L. 



1. Winter-buds glabrous, glutinous, 1-2 cm long; leaflets lanceolate, 

 acuminate, finely serrate, 5-9 cm long; flowers 5-6 mm broad; 

 fruits 4-6 mm in diameter; rocky woods, rare, near Oregon, 

 Ogle Co., June 2, 1888, M. B. Waite; now probably extinct in 

 111. American Mountain-ash S. americana Marsh. 



16. Aronia Medic. — Chokebeny 

 1. Inflorescence and lower surface of leaves nearly or quite glabrous; 

 fruit black, soon falling; moist sandy woods, and edges of bogs 

 in northern 111.; also on exposed sandstone cliflfs in southern 

 111., Saline Co., Mohlenbrock & Voigt in 1958. May-June. 

 Black Chokeberry A. rnelanocarpa (Michx.) Ell. 



1. Inflorescence and lower surface of leaves tomentose; fruit purplish- 

 black, long-persistent; Cook, Kankakee, and Winnebago coun- 

 ties. Purple Chokeberry A. prunijolia (Marsh.) Rehd. 



17. Pyrus L. — Pear 

 P. communis L. Cultivated and found occasionally as an escape 

 in woods or along roads; native of Eur. May. 



18. Malus Mill. — Apple 



1. Calyx glabrous outside (rarely somewhat villous) ; leaves glabrous 

 or nearly so; mature fruit 1-3 cm in diameter; woods in the 

 southern half of 111. Apr.-May. Wild Sweet Crabapple. [Pyrus 

 coronana L.; M . angustifolia (Ait.) Michx.; M. lancifolia 

 Rehd.] M. coronana (L.) Mill. 



1. Calyx tomentose; leaves pubescent beneath, at least along the 

 veins. 



