Washer Install questions.

I have a first floor hookup and I have to drop it to the basement. My new installation would be directly beneath. My question is can I drain directly to the stack which sits right behind the washer, or would I have to install a standpipe?

My wife has great reservations about me doing this, however with everything right above it seems like a no brainer.

Thanks.

You must have a standpipe with a trap.