ROSACEAE 99 



PHYSOCARPUS Rafinesque 

 The Ninebarks 



The ninebarks are shrubs with exfoliating bark, which bear 

 alternate. 3- to 5-ribbed and more or less lobed leaves usually 

 pubescent with more or less stellate hairs. The flowers occur 

 in terminal corymbs and have 5 persistent sepals and 5 white or 

 pinkish petals, 20 to 40 stamens, and 1 to 5 pistils, which are 

 more or less united at the base. The fruit at maturity is a 

 more or less inflated capsule which opens along both sutures, 

 and the shiny, bony-coated seeds are obliquely pear shaped. 



Key to the Ninebark Species 



Leaves ovate, carpels usually 5 and glabrous P. opulifolius 



Leaves suborbicular, carpels 3 or 4 and finely pubescent 



P. intermedius 



PHYSOCARPUS OPULIFOLIUS (Linnaeus) 



Maximowicz 



Common Ninebark 



The Common Ninebark, fig. 22, is a much-branched and 

 spreading shrub, reaching occasionally 9 or 10 feet in height; 

 the old bark exfoliates in long, thin strips. The branchlets and 

 the upper branches are more or less pubescent. The kaves are 

 ovate to nearly orbicular and more or less definitely 3-nerved, 

 sometimes also 3-lobed, and for the most part cordate or trun- 

 cate at the base. They are glabrous, 1 to 2 inches long on the 

 fruiting branches and on the sterile branches often almost 

 twice as large. The margins are irregularly and doubly crenate, 

 and at maturity the surface is smooth or nearly so above but 

 more or less pubescent beneath, at least on the main nerves. 



The white flowers occur in terminal corymbs in May or early 

 June, 25 or more in a cluster. The sepals are ovate, acute, and 

 pubescent inside and out, and the petals are broadly ovate to 

 nearlv orbicular and more or less pubescent on both sides. 

 The fruit, which matures from the last of July into September, 

 consists of 3 to 5 follicles 14 to i/^ inch long, which are glabrous 

 and shining, obliquely awl tipped, and about twice as long as 

 the calyx. The glossy, very light brown seed is obliquely ovate 

 and hardly one-sixteenth inch long. 



Distribution. — The Common Ninebark is a shrub of 



