how to list categories without heading?

How do you print a list of categories, but not include the heading? This is the code I have right now, which came as part of an existing template:

<?php wp_list_categories('orderby=name&show_count=0&title_li=<h2>Categories</h2>');
?>

Problem is, it displays this:

Categories
cat1
cat2
cat3…etc

I just want this:

cat1
cat2
cat3…etc

…without the “Categories” heading. How do I do this?