<PAGE>

EXHIBIT 10.21


THIS NOTE AND THE COMMON STOCK OF THE COMPANY HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933. AS AMENDED (the "ACT"), OR QUALIFIED UNDER ANY STATE
SECURITIES LAWS AND HAVE BEEN ACQUIRED FOR INVESTMENT PURPOSES ONLY AND NOT WITH
A VIEW TO OR FOR SALE IN CONNECTION WITH ANY DISTRIBUTION THEREOF. THIS NOTE AND
THE COMMON STOCK OF THE COMPANY MAY NOT BE SOLD, ASSIGNED, OR OTHERWISE
TRANSFERRED UNLESS THEY ARE REGISTERED UNDER THE ACT AND ANY APPLICABLE STATE
SECURITIES LAWS OR THE COMPANY RECEIVES AN OPINION OF COUNSEL FOR THE HOLDER
CONCURRED IN BY COUNSEL FOR THE COMPANY THAT REGISTRATION AND QUALIFICATION ARE
NOT REQUIRED.


                                   PENGE CORP.
                                 PROMISSORY NOTE

$__________                                        Issue Date: _________________


FOR VALUE RECEIVED, _________________ (the "Company"), hereby promises to pay to
the order of _________________ (the "Holder") in the amount of _______________,
with simple interest at the rate of _________________ per annum.

Interest will be calculated on a 365-day year for the actual number of days
elapsed and shall commence on the Issue Date and continue on the outstanding
principal until paid in full or converted as provided below.

l.       Purchase Terms. This note (the "Note") is issued pursuant to the terms
         outlined below and dated _________________.

         o        The note is a twenty four month note.

         o        The note carries annual interest payments due on ____________.

         o        A $_________ balloon of the principal is due on _____________.

2.       Maturity Date. The entire outstanding principal balance of this Note,
         and any unpaid accrued interest, shall be due and payable in full on
         the date that is ___ months from the Issue Date first set forth above
         (the "Maturity Date") unless prepaid or converted by the Holder prior
         to the Maturity Date pursuant to the terms of this Note.

3.       Payment. All amounts payable hereunder shall be paid by the Company in
         immediately available and freely transferable funds at the place
         designated by the Holder to the Company for such payment.

4.       Successors and Assigns. All covenants, agreements and undertakings in
         this Note by or on behalf of any of the parties shall bind and inure to
         the benefit of the respective successors and assigns of the parties
         whether so expressed or not.

<PAGE>

5.       Severability. If any provision of the Note is held to be illegal,
         invalid or unenforceable under any present or future law, then: (i)
         such provision, or any portion thereof, shall be fully severable; (ii)
         this Note will be construed and enforced as if such illegal, invalid or
         unenforceable provision had never comprised a part hereof; (iii) the
         remaining provisions of this Note shall remain in full force and effect
         and shall not be affected by the illegal. invalid or unenforceable
         provision or its severance from this Note; and (iv) in lieu of such
         illegal, invalid or unenforceable provision there will automatically be
         added as a part of this Note a legal, valid and enforceable provision
         on terms as substantially similar as possible to the terms of the
         illegal, invalid or unenforceable provision.

6.       Amendment. This Note and any provision hereof may be changed, waived,
         discharged or terminated only by an instrument in writing signed by the
         Company and the Holder.

7.       Governing Law. The terms of this Note shall be construed in accordance
         with the Laws of the State of Nevada as applied to contracts entered
         into by Nevada residents within the State of Nevada, which contracts
         are to be performed entirely within the State of Nevada.

8.       Notice. Any notice or other communication provided for under this Note
         shall be in writing and shall be sent by (a) personal delivery, (b)
         registered or certified mail (return receipt requested) or (c)
         nationally recognized overnight courier service, to Company or to the
         Purchaser at their respective addresses set forth on the signature
         pages of the Agreement. A notice or other communication shall be deemed
         to have been duly received (a) if personally delivered, on the date of
         such delivery, (b) if mailed, on the date set forth on the signed
         return receipt or (c) if delivered by overnight courier, on the date of
         actual delivery (as evidenced by the receipt of the overnight courier
         service).

9.       Collateral. The Company agrees to provide _________ trees on the Major
         Trees Arizona Farm as collateral for this note and agreement. The trees
         will be secured by UCC-l filing within 20 days of the signing of this
         note, filed by the Company in the state of Arizona.

IN WITNESS WHEREOF, the Company has caused this Note to be issued as of the date
first written above.

                                         PENGE CORPORATION

                                         By: ________________________________

                                         Name: ______________________________

                                         Title:______________________________

                                         Date: ______________________________


                                         Lender:

                                         By: ________________________________

                                         Name: ______________________________

                                         Signature: _________________________

                                         Date: ______________________________