display post category (specific)

After googling to no avail. I am simply looking to display a section in the sidebar that contains a section where all posts tagged in the category “pictures” is displayed as they are written.

So if I write a post “pictures of evan” in category ‘pictures’ it will display in the sidebar as

PICTURES
pictures of evan
christmas 2006
thanksgiving
easter
surgery

wp_list_categories(‘display pictures category’);