How to use nth-child for styling with a table with rowspan?

What seems to work for me is to put a td in the row below with display:none

<table>
   <tr>
      <td rowspan="2">2 rows</td>
      <td>1 row</td>
   </tr>
   <tr>
      <td style="display:none"></td>
      <td>1 row</td>
   </tr>
</table>