what I am trying to accomplish is this image:

now what I’ve done so far is:
<ul class="flechalista">
<li><a href="#">2012</a>
<ul class="flechalista">
<li>Enero</li>
<li>Febrero</li>
<li>Marzo</li>
<li>Abril</li>
</ul>
</li>
</ul>
and my css is this:
.flechalista{background:#fff;}
.flechalista li{background:#fff url(../img/red_arrow.png) no-repeat 10px 4px; padding:5px 0 5px 30px !important; border-bottom:1px solid #000;}
Now this works except that as you can see the border-bottom is for every li and full width.
I think I could make a first LI with less padding(2012) and the months LI’s would have a bit more padding. But is there a way using what i have an playing with the css make it work?
Demo: http://jsfiddle.net/calder12/FSa2S/5/