ROSACEAE 101 



marshes and low woods. It is to be found in such situations 

 from Quebec westward into Iowa and south to Georgia and 

 Tennessee. It occurs in suitable habitats throughout the state 

 of Illinois, but has been reported much more frequently in the 

 northern part than in the southern, where it evidently is rare 

 and perhaps definitely localized. 



PHYSOCARPUS INTERMEDIUS (Rydberg) Schneider 



Illinois Ninebark 



The Illinois Ninebark, fig. 22, is a shrub very similar in gen- 

 eral appearance, foliage, and flowers to the Common Ninebark. 

 It may be distinguished, however, by the fact that its leaves 

 are mostly narrower and narrowed to the petiole at the base. 

 Also, the calyx is densely stellate pubescent and the follicles, 3 or 

 4 per flower, are abruptly acuminate and permanently stellate 

 pubescent. It is a lower shrub than the Common Ninebark, 

 seldom more than 4i/4 feet tall. 



Distribution. — The Illinois Ninebark ranges from New 

 York westward into South Dakota and southward into Missouri 

 and Arkansas. In Illinois, it is a relatively rare shrub that has 

 been infrequently recorded, mostly in the southern and south- 

 eastern part of the state. 



By some authorities, this second species is believed to be 

 merely a variety of the first, distinguished entirely on the basis 

 of its permanently pubescent follicles. Material collected in 

 Illinois does not show the intergrading, in this respect, that 

 Deam has observed in his probably much more numerous In- 

 diana collections. 



SPIRAEA (Tournefort) Linnaeus 

 The Meadowsweets Spireas 



The meadowsweets are shrubs with alternate, pinnately 

 veined and usually simple leaves but no stipules. The flowers 

 are perfect, with 5 sepals, 5 white to red petals, 15 to 70 sta- 

 mens and 5 or, rarely, as few as 3 or as many as 8 distinct 

 pistils. The flowers are variously aggregated into racemes, 

 corymbs or panicles. The fruits are leathery follicles which 

 are not inflated and which open along 1 suture and contain, 

 usually, 4 seeds which taper at both ends. 



