Invisible object, visible texture, how?

Support Basics & Interface
1

I got a texture of a leaf with alpha channel. But when I apply the texture to a plane, the default gray is visible where the leaf is transparent.

Turning material alpha slider to 0 will make the texture invisible as well. So how to make the object invisible, and only the texture visible?

2

you will need to map it to the alpha as well as the color

3

Texture:

http://img50.imageshack.us/img50/1930/vaahterahighres.png

Render:

http://img10.imageshack.us/img10/9194/vaahterarender.png

So what do I have to do, exactly? I have checked both “Col” and “Alpha” in “Map To” panel.

EDIT: Turned alpha slider to 0, renders correctly.