The red-pea gall or red currant gall develops as a chemically induced distortion arising from the underside of the mid-rib of a vein on Quercus species and it is attached by a short stalk or peduncle.

[1] In appearance it is glossy and somewhat flattened sphere and from ten to fifteen or so may occur on a single leaf.

The average size is 5 by 6 millimetres (0.20 in × 0.24 in) and the colouring starts as green, passing to yellow, orange and then red-brown; the season is midsummer onwards.

The infested buds become yellow, orange or a russet colour and are about 4 mm (0.16 in) long.

The interior of a bedeguar gall is formed from the bud, and is composed of edible nutritious and structural tissues.