2009 California Penal Code - Section 37-38 :: Title 3. Of Offenses Against The Sovereignty Of The State

37.  (a) Treason against this state consists only in levying war
against it, adhering to its enemies, or giving them aid and comfort,
and can be committed only by persons owing allegiance to the state.
The punishment of treason shall be death or life imprisonment without
possibility of parole. The penalty shall be determined pursuant to
Sections 190.3 and 190.4.
   (b) Upon a trial for treason, the defendant cannot be convicted
unless upon the testimony of two witnesses to the same overt act, or
upon confession in open court; nor, except as provided in Sections
190.3 and 190.4, can evidence be admitted of an overt act not
expressly charged in the indictment or information; nor can the
defendant be convicted unless one or more overt acts be expressly
alleged therein.

38.  Misprision of treason is the knowledge and concealment of
treason, without otherwise assenting to or participating in the
crime. It is punishable by imprisonment in the state prison.