1 30 MALACEAE 



faces are long pubescent at first, but the upper surface soon 

 becomes glabrous or nearly so and the lower surface remains 

 pubescent until maturity. The rachis is usually long pubescent, 

 channeled above, and bears a cluster of glands in the channel 

 at the base of each leaflet. Lateral leaflets are sessile, or nearly 

 so, and terminal leaflets stand on a stalk ]4 to l/^ inch long. 

 The stipules are obovate and glandular-serrate, and the upper 

 margin is elongated and tipped with a bristle-like gland. 



The white flowers appear late in May in terminal cymes. 

 The calyx tube is pubescent at first but soon becomes glabrous. 

 The fruit, which matures in late August or September, is a 

 small, globose, bright red pome a little less than 14 i^^ch in 

 diameter, which as a rule contains 1 seed. 



Distribution. — ^The Western Mountain- Ash is an inhabitant 

 of the far north with a natural range which extends from Lab- 

 rador to Minnesota and south to Pennsylvania and Iowa. Its 

 occurrence in Illinois at the present time is to be doubted, al- 

 though two specimens collected in Lake County nearly half a 

 century ago show that it was a member of the state's flora. 



ARONIA Medicus 

 Chokeberry Chokepear 



The chokeberries are low shrubs which bear simple, alternate, 

 serrate leaves, small, deciduous stipules, and small, perfect flow- 

 ers in terminal, compound cymes. There are 5 distinct sepals, 

 5 white or pink, spreading petals, numerous stamens, and a 3- to 

 5-celled ovary capped by 3 to 5 basally united styles. The fruit 

 is a small, globose pome capped by a persistent calyx. 



This genus consists of only three species, all restricted to 

 North America. The following occur in Illinois. 



Key to the Chokeberry Species 



Branchlets, calyx and pedicels more or less pubescent .^ 



A. prunifolia 



Branchlets, calyx and pedicels glabrous A. melanocarpa 



ARONIA PRUNIFOLIA (Marshall) Rehder 

 Purple Chokeberry 



The Purple Chokeberry, fig. 30, is a shrub which grows 3 to 9 

 feet high, with smooth or somewhat roughened bark somewhat 



