date format connecting through java and via SQL Plus appears to differ

Hello all.

This is something that I am having problem understanding. I have a v11 database. When I connect via SQL Plus and run select sysdate from dual; I  get this result

SQL> select sysdate from dual;

SYSDATE
---------
07-MAR-13

nls_date_format is not defined

SQL> show parameter nls_date_format

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
nls_date_format                      string

But I do see this parameter in nls_database_parameters

  1  select * from nls_database_parameters
  2* where parameter = 'NLS_DATE_FORMAT'
SQL> /

PARAMETER
------------------------------
VALUE
--------------------------------------------------------------------------------
NLS_DATE_FORMAT
DD-MON-RR

This format DD-MON_RR is consistent with the result of my query.