Whortleberry

A name used for various kinds of low-lying shrubs that produce bright berries. Whortleberries are often found in areas of woodland or forest, and in Middle-earth they were recorded in regions as far apart as Lórien and Ithilien.

The name whortleberry is applied to a variety of different plants, and so it is difficult to identify precisely which of these was intended by Tolkien. Some varieties are also known as bilberries, but since bilberries are referred to several times as separate plant, we can probably discount these. The whortleberry's most likely intended identity, then, would be Vaccinium vitis-idaea, the red whortleberry (also known as the lingonberry or cowberry) which produces clumps of brilliant red berries. (An alterative might be Gaylussacia, which is also sometimes known as a whortleberry, but as this plant is native to the Americas, it was unlikely to have been found growing wild in Middle-earth.)