SQL & PL/SQL

Hi there,

I am using Oracle 10 and I have the following table:

Id    Name            Region   
------------------------------
1     Acer             3       
1     Betula          1       
1     Corylus         2       
1     Fagus           1       
1     Fagus           2       
1     Fagus           3      
2     Alnus viridis   1       
3     Corylus         1       
4     Acer            7       
5     Fagus           4       
6     Acer            6
6     Fagus           9
7     Fagus           8
8     Acer            2

I want to select all rows where Name equals "Acer" or "Fagus" but I want only get records with same Id.
My result should read like this:

Id    Name            Region   
------------------------------
1     Acer            3        
1     Fagus           2       
1     Fagus           3      
6     Acer            6
6     Fagus           9

How do I need to write my SQL Query?

I tried using UNION but this is a real performance killer.
Here is what I tried:

 SELECT Id, Name, Region
      FROM mydatenview
      WHERE               
        Name = 'Acer'
        AND Region = 3
        AND Id IN (SELECT Id
                          FROM mydatenview
                          WHERE                                   
                             (Name = 'Fagus'
                              AND Region = 1)                                 
                            ) 
UNION
 SELECT Id, Name, Region
      FROM mydatenview
      WHERE               
        (Name = 'Fagus'
         AND Region = 1)
        AND Id IN (SELECT Id
                          FROM mydatenview
                          WHERE                                   
                             (Name = 'Acer'
                              AND Region = 3)                                 
                            ) 
ORDER BY Id, Name

Thank you in advance for tips.

Regards,
Nico