By the latest enactments (one dating from 1905) 2500 citizens can claim a vote ("facultative referendum") as to any legislative project, or can exercise the "right of initiative" as to any such project or as to the revision of the cantonal constitution.
Some fungi, though able to live as saprophytes, occasionally enter the body of living plants, and are thus termed facultative parasites.
Since 1875, 1000 citizens can claim a popular vote (facultative Referendum) on all bills, or can exercise the right of initiative whether as to laws or the revision of the cantonal constitution.
The provisions of neither convention are obligatory, but merely " facultative," amounting only to recommendations.
Their metabolic products may induce blood-poisoning or other toxic effects (facultative parasites) though they are not true parasites.