gem namespaces within rails class

I'm brand new to rails (and ruby) and having a a lot of trouble with accessing different namespaces. Specifically, I can't access the namespace of the flickraw gem from within a controller class:

class ImageSourcesController < ApplicationController
    def show
        list   = flickr.photos.getRecent
        ...
    end
end

Calling this method, I get the response:

undefined local variable or method `flickr' for #<ImageSourcesController:0x00000005006658>

I am using bundler, which I thought ensured that the methods of all gems in the gemfile are required by rails.