[blackdog]

Rose hip
The rose hip, also known as rose haw or rose hep, is the fruit of the rose plant, that typically is red-to-orange, but ranges from dark purple to black in some species. WikipediaNutrition Facts
Rose hipsAmount Per 100 grams
Calories 162

% Daily Value*
Total Fat 0.3 g 0%
Sodium 4 mg 0%
Potassium 429 mg 12%
Total Carbohydrate 38 g 12%
Dietary fiber 24 g 96%
Sugar 2.6 g
Protein 1.6 g 3%
Vitamin A 86% Vitamin C 710%
Calcium 16% Iron 6%
Vitamin B-6 5% Magnesium 17%
*Per cent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
Sources include: USDA

[djf]

Plain ordinary dandelion leaves are also high in Vit C.

Another plant that grows like a weed where I live - red sorrel - has it too.