Weeds That 
Ride the Rails 
Railroads can be a good way for a plant 
to disperse — if it can take the heat and 
doesn V lose its head 
by Robert M. Arnold 
The sight, sounds, and smells of steam 
locomotives are among my earliest memories, 
and they still evoke a nostalgia for childhood 
hours spent on bridges or behind fences, 
watching trains go by. Today, despite the 
replacement of steam by diesel and the 
reduction in the frequency of trains, a walk 
along a railroad track is one of my favorite 
activities. While walking along a seldom-used 
rural line in Madison County, New York, 
several summers ago, I became aware of the 
profusion of weeds growing on the cinders of 
the railbed. I soon noticed patterns in their 
distribution and began to wonder about the 
adaptations that might be necessary for a plant 
species to colonize what seems, at first sight, 
such an inimical environment. What started as 
casual curiosity led to speculations that would 
become the major focus of my research. 
As enjoyable places to study weeds, 
railroads have no equal for me. Just 
