Git show all branches (but not stashes) in log

I have a Git alias that expands to:

git log --graph --oneline --all --decorate

According to man git log there are a couple of suspicious options: --not and --branches; but I can't make it work properly.

How should I edit that to hide the stashes?

FYI: as per the accepted question and comment my .gitconfig alias now looks like this:

[alias]
    l = log --branches --remotes --tags --graph --oneline --decorate --notes HEAD

Instead of doing --all and then trying to filter out the stashes, don't ever include them in the first place:

git log --branches --remotes --tags --graph --oneline --decorate

The main problem that arises from trying to filter them out afterwards is that if the stash is the latest commit on that branch (because even though it's not the head of the branch, it's still the most recent descendant of it), it can actually filter out the entire branch from the log, which isn't what you want.

My alias:

[alias]
    l = log --oneline --decorate --graph --exclude=refs/stash

In this case you will be able to use these forms without showing the stash:

• git l for the current branch
• git l feature234 for a specific branch
• git l --all for the overall history

From the manual:

--exclude=<glob pattern>

Do not include refs matching that the next --all, --branches, --tags, --remotes, or --glob would otherwise consider.

Note that Andrew's answer wouldn't work for hiding StGit^1.) branches <branch>.stgit (from StGit version 0.15) which otherwise litter the output making it unusable.

Currently I use the following solution:

$ git log --graph --oneline --decorate \
  $(git for-each-ref --format="%(refname)" refs/heads/ refs/remotes/ |
    grep -v "\.stgit$")

^1.) StGit ("Stacked Git") provides Quilt/mq--like functionality to Git (i.e. pushing/popping patches to/from a stack).