The distribution is paid in cash. If you are signed-up for a dividend reinvestment plan, your broker will purchase the shares at some point shortly after the cash is received (often at not the best price).
Ohio, thanks for that. I used to think the reinvestment was a good idea to save the commssion. But the price never seemed to match the market price. Way higher. I concluded I am better off paying the commission and just picking up things that were down or diversifying to new companies.