railroad tracks are a common place to find native plants. railroads typically were in place a long time before a lot of disturbance of adajcent lands would have been done. the best thing to do is to collect seeds from the plants rather than moving the plants. queen anns lace is invasive so it should not be propogated. if the plants are in danger from disturbance or construction then removing wont do them any harm because they would be lost anyway. late summer is not the best time of year for transplanting... early spring is better.
if you do move them - you do need to dig them - not pull them... and dig as much of the surrounding dirt as seems reasonable to get as much of the root as is feasible... and then when you tranplant it - keep all of that dirt right with the transplant... and water the heck out of 'em after they are transplanted...

when digging plants from the wild - look at the surroundings, is the plant a single plant or a in a meager stand of a few plants, that if you removed one plant there would be little or nothing left from its wild spot...if so, then i would reconsider disturbing it... in a healthy stand of vigours numerous plants, with proper permission on private property, then i would say transplanting is okay.

plants should not be removed from public parks or right of ways without proper authority.

while i say this: i must also say that you should be aware that the railroad can charge you for tresspassing on their property and removing the plants is against the law without their permission... i felt i needed to say that so that i would not be considered a co-conspirator in illegal activities.

well, we wave to the guys on the tracks all the time. these tracks are used maybe once every two weeks for transport. their fastest speed is like 20 mph. i would not take plants that were rare, etc, like trilliums or something. I'm just talking about wildflowers that there are TONS of. anyway i think they'd be more interested in charging the kids who go down there to drink and smoke pot and think that place is their own personal dump!
You're not REALLY worried are ya?
alida

no - i really wasnt concerned that you would get in trouble. i dont want to encourage illegal activity - even if i do partake of it myself ;-) i have been known to collect plants from the railroad ... in my area they spray the right of way with weedkiller (2-4-D i think) - so i try to collect as much as i can before they kill everything...
the railroad right of way has been a good source for me; to name a few: trillium, spiderwort, cupplant, bottlebrush grass, sweet cicely, solomens seal, delphinum and false solomens seal.
i do know that its standard practice for the railroad to press tresspass charges whenever someone is hit by a train...kind of a hedge in case of a lawsuit. where my parents live - there is a train superhighway... double track, with trains travelling 60 mph and there is one or two every hour...so its inevitable that someone gets smacked every once in awhile...

Railroad tracks are also a wonderful place to find those "wildflowers" that turn out to be highly invasive aliens. Do be careful what you decide to transplant.