Subornation of perjury is the crime of persuading a person to commit perjury; and also describes the circumstance wherein an attorney causes or allows another party to lie.
It's pretty clear this, not magic, is the end goal of the original statement.
You've misunderstood the Wikipedia article, which is not surprising because it is poorly written. The government can establish mechanisms for people to provide statements "under penalty of perjury", such as IRS forms. But the mere words "under penalty of perjury" aren't a magic incantation; they have force only when specifically given it by the government.
"Under penalty of perjury" is just a mechanism for substituting a written declaration for an in-person swearing.
If you look at the statute, the governing condition is (paraphrased) "under laws or circumstances requiring or permitting a sworn statement".
http://en.wikipedia.org/wiki/Perjury
The rules for perjury [apply] even if the person has not been sworn or affirmed as a witness before an appropriate official.
Also relevant:
http://en.wikipedia.org/wiki/Subornation_of_perjury
Subornation of perjury is the crime of persuading a person to commit perjury; and also describes the circumstance wherein an attorney causes or allows another party to lie.
It's pretty clear this, not magic, is the end goal of the original statement.