Oregon Grape, Red Leaves and bearing fruit

In "How Plants Work" red leaves (anthrocyanins) of the Oregon grape are used to illustrate how the red pigments can protect a plant from the cold.  The photo was taken on a relatively cold, (fifties), day in May but no snow in sight.  There is a long list of normal and stressful reasons for the leaves to turn red, nutrition, toxins, soil acidity, temperature and variations in metabolism.  Both bushes shown here were near the road, possibly exposed to more chemicals and salt. Every leave has a tale to tell.

This May(2017)we are concentrating on differences from the weekly notes last year.  In this case I do not remember seeing the grapes on the Oregon grape, said to be useful for jam or jelly.

Red(anthrocyanins) leaves on Oregon grape,possible roadside stress

Grapes of the Oregon grape

Another roadside plant with red leaves, Maples can vary, possible stress.