A very good tea with vitamin C content is Rose Hip. Unfortunately, I can't handle the taste. I love to mix it with chamomile. It makes for a nice tasty tea blend!
Here is what simple Wikipedia says about it:
"Medical usesRose hips are particularly high in vitamin C content, one of the richest plant sources available. However, RP-HPLC assays of fresh rose hips and several commercially available products revealed a wide range of L-ascorbic acid content, ranging from 0.03 to 1.3%.[2] Rose hips of some species, especially Rosa canina (Dog Rose) and R. majalis, have been used as a source of vitamin C. During World War II, the people of Britain were encouraged through letters to The Times newspaper, articles in the British Medical Journal, and pamphlets produced by Claire Loewenfeld, a dietitian working for Great Ormond Street Hospital for Sick Children, to gather wild-grown rose hips and to make a vitamin C syrup for children. This was because German submarines were sinking many commercial ships: citrus fruits from the tropics were very difficult to import.
Rose hips also contain some vitamin A and B, essential fatty acids and antioxidant flavonoids.[citation needed]
A study of a rose-hip preparation for treating rheumatoid arthritis concluded that there was a benefit, apparently due to both anti-inflammatory and anti-oxidant effects.[3]
Rose hips are used for colds and influenza."