Yes, that's right, the fibers running up and down the stalk. THere are several ways you can extract the fibers, one is by retting, I believe you keep it submerged in water untill the stalk starts to rot away, then pulling the fibers free. or you can simply break the inner stalk (the fibers won't, or shouldn't break with it), then pulling the fibers out.
Hope this helps.
Sean