263] FLORA OF COLUMBIA AND VICINITY 121 



286. P, monilifera Ait. [P. deUoides Marsh.]. Cotton- 

 wood. 



Common along streams. 



Quebec to the Northwest Territory; Florida to New 

 Mexico. 



106. SALIX L. Willow. 



287. S. nigra Marsh. Black willow. 



A common tree along streams: intermediate forms con- 

 nect this species with both S. longipes Anders, and S antyg- 

 dahides Anders. 



New Brunswick to Michigan, Western Ontario and 

 SoiTTH Dakota; Florida to California. 



287 a. S. nigra falcata (Pursh) Torr. 

 With the type; frequent. 

 Massachusetts to Michigan; Florida to Missouri. 



288. S. longipes Anders. \S. nigra Wardii Bebb: S. 

 Wardii Bebb]. 



Common along streams. 



Maryland to Missouri; Florida to Texas. 



289. S. amygdaloides Anders. Peach-leaved willow. 

 Abundant along streams. 



Quebec to British Columbia; New York to Missouri, 

 Texas and Oregon. 



290. S. alba L. White willow. Sallow. 

 Commonly planted for ornament, and escaped along 



streams especially in the city of Columbia. 

 Europe, thence to North America. 



291. S. longifolia Muhl. \S. fluviatilis Nutt.: S. interior 



Rowl.]. Sand bar willow. 



Sandy flats along streams and the margins of lakes; blos- 

 soming often in late summer. 



Quebec and Maine to Virginia; westward across the con- 

 tinent. 



292. S. humilis Marsh. Prairie willow. 



Two shrubs, one pistillate, the other staminate, along the 



