The pleadings shall be in writing and shall be verified. The petition shall describe with reasonable certainty the property proposed to be taken, and may embrace one or more parcels of land where the ownership is the same. If an estate less than a fee is proposed to be taken, the petition shall describe with reasonable certainty the particular estate less than the fee which it is proposed to take, the name of the owner or owners thereof, the manner and extent of their respective interests. If there are any liens upon or conflicting claims to such real estate, the petition shall state the nature and amount of such liens and claims and the names and places of residence of the persons who hold the same, so far as known to the petitioner. Where there are persons interested in the property proposed to be taken whose names are unknown to the applicant, or it is not known to the applicant whether there are any other persons interested in the property proposed to be taken, or there be any contingent or executory interest or estate in such property which is liable to vest in or to open and let in persons not in being, such fact shall be stated in the petition and such persons, if any, shall be made parties defendant to such petition by the general description of parties unknown. The joinder of any person having only a contingent or executory interest in the property proposed to be taken shall not be necessary when the person not joined is virtually represented by any other party or parties defendant; and where such virtual representation exists no order or decree made thereunder shall be deemed erroneous or void because of such nonjoinder. The petition shall also state the use to which the estate sought to be taken is intended to be appropriated.