Combine orange, rhubarb and sugar in a Dutch oven. Bring to boil, stirring constantly. Boil, stirring occasionally, until thick. Add saskatoons and lemon juice. Boil, stirring frequently until thick, about 15 minutes. Pour into hot sterilized jars, leaving 1/4 inch headspace. Wipe jar rims thoroughly. Seal and process ina boiling water bath for 10 minutes.
Yield: 16 cups.