Party Chairman John Dixon praised Ieuan Wyn Jones
Plaid Cymru bosses have called on the party to unite, ahead of a leadership contest to find a successor to Ieuan Wyn Jones.
Chairman John Dixon appealed for the party to "draw a line under recent events" as the party's National Executive (NEC) met in Aberystwyth to discuss Plaid's poor performance in the Welsh assembly election.
Mr Jones stood down on Thursday after Plaid lost five of its 17 seats.
He ended his three-year leadership of Plaid after being told he had lost the support of half of the party's remaining 12 AMs.
The party is the ownership of its members, not a bunch of prima donnas and vipers in Cardiff Bay
Director of Elections, Elwyn Vaughan
But Mr Dixon praised the former leader's contribution to Plaid Cymru and called for party unity.
He said: "The NEC put on record its great appreciation of the tireless work of Ieuan Wyn Jones during his presidency and noted his exceptional contribution to the development of Plaid Cymru over the years.
"The NEC now urges all members to draw a line under recent events and unite behind Plaid Cymru."
The chairman's comments followed criticism by some figures of the Assembly Members who told Mr Jones they had lost confidence in his leadership.
Director of Elections, Elwyn Vaughan, told BBC Wales: "The party is the ownership of its members, not a bunch of prima donnas and vipers in Cardiff Bay."
Plaid plans to elect a new leader by their party conference in mid-September.
Elwyn Vaughan hit out at 'vipers'
Nominations for the presidency will open on Monday.
Campaigning is expected go on through the summer with nominations closing on 4 July.
It is hoped the new leader will be in place by the party conference in mid September.
Mr Jones did not attend the national executive meeting.
A spokesman said he had decided to take the weekend off.
Several Plaid figures have indicated that they may stand in the leadership election.
Plaid is beginning the search for Ieuan Wyn Jones' successor
Plaid's parliamentary leader, Elfyn Llwyd, who leads Plaid's four MPs at Westminster, has not ruled out standing in any leadership election.
He said: "My gut instinct is if I thought that those candidates who put their names forward were not acting in the best interests of the party, then I would be persuadable."
Pauline Jarman, the leader of Rhondda Cynon Taff Council, has already said that she may fight for the party's top job.
She said: "I've been approached and I'll let the public know whether or not I've decided to throw my hat into the ring presently."
Other possible candidates include AMs Helen Mary Jones and Rhodri Glyn Thomas, and MEP Jill Evans.
Another is the MP Adam Price.
But several leading figures have ruled themselves out.
They included former leader Dafydd Wigley, Ceredigion MP Simon Thomas and AMs Janet Ryder and Dai Lloyd.
Mr Jones' departure will lead to the second Plaid leadership contest in three years.
The Ynys Mon AM won by a huge majority of party members in summer 2000, but he leaves no obvious successor.
Mr Jones will remain both party president and leader of the assembly group until the leadership election.