391] FLORA OF COLUMBIA AND VICINITY I49 



Common along streams and in bottom lands. 



Maine to Minnesota and Nebraska; Florida to Texas. 



Family 51. ROSACEAE Juss. Rose family. 



186. PHYSOOARPUS Maxim. [OPULASTER 

 Medic: SPIRAEA L.: NEILLIA Don.]. Nine- 

 bark. 



462. P. intermedius (Rydb.) Daniels \_0. intermedins 

 Rydb.]. 



Rocky banks of streams; scarce. 



Illinois to South Dakota; Alabama to Colorado. 



463. P. Missouriensis Daniels. Nov. spec. Missouri 

 nine-bark. 



Shrub 2 to 3 m. high with shreddy bark and recurved branch- 

 es; leaves broadly ovate, with inequally serrate margins^ 

 often more or less three-lobed, stellate-pubescent when 

 young, the pubescence persisting along the midribs and 

 veins of the mature leaves, which are cuneate to subcordate 

 at the base; flowers in umbel-like corymbs, white or pinkish 

 green; the pedicels and calyces densely stellate-pubescent 

 when young, but conspicuously so when mature. Along 

 cliffs and rocky banks. 



Missouri; St. Louis County (E. H. Favor), Boone Coun- 

 ty (Chas. Thorn; F. P. Daniels), Jackson County (B. F- 

 Bush).* 



*The following may serve as a synopsis ot the species of Physocarpus 

 Maxim. \Opulaster Medic] occurring in the eastern United States: 

 A. Pubescence stellate. 



1. Leaf-blades densely pubescent when mature. 



P. ferrugineus (Nutt.) Daniels [O. stcllatns Rydb.: 5". 

 opiilifolia ferru^hiea Nutt.]. 



2. Leat-blades sparsely pubescent when mature, or nearly glab- 



rous. 



a. Follicles stellate-pubescent. 

 P. Missouriensis Daniels. 



b. Follicles glabrous or nearly so. 



p. Michiganensis Daniels. Nov. spec. 

 Shrub 1-3.5 m. high with shreddy bark and recurved branches; leaves 

 ovate, cuneate, or occasionally truncate at the base, mostly slightly 

 three-lobed, the margins doubly, but inequally serrate, densely stellate- 

 pubescent when young, sparingly so when mature, especially underneath 

 along the veins; flowers in rounded umbel-like corymbs, usually white 



