I have collected several recipes from my grandmothers. This one is from my Grandma Edith.

Pastry for 9 inch pie
3 eggs, separated
1 1/4 c. sugar
1/4 c. butter, softened
3 tbsp. frozen orange juice concentrate
1/4 c. flour
1/4 tsp. salt
2 1/2 c. rhubarb, cut into sm. pieces
1/3 c. chopped pecans

Beat egg whites until stiff. Add 1/4 cup sugar gradually; beating well. Mix butter and orange juice concentrate with egg yolks, beat thoroughly. Add 1 cup sugar, flour and salt; beat well. Add rhubarb to yolk mixture. Gently fold in meringue. Pour into pie shell. Sprinkle with nuts. Bake at 375 degrees for 15 minutes then reduce heat to 325 degrees and continue baking for 45 to 50 minutes.