Hunting at Roadside IV #17

Hydrangea Macrophylla is a deciduous shrub growing broad with large heads of pink or blue flowers in summer and autumn.

Blooms can be blue, red, pink, light purple, or dark purple depend on soil pH. An acidic soil (pH below 7) will usually produce flower color closer to blue, whereas an alkaline soil (pH above 7) will produce flowers more pink. This is caused by a color change of the flower pigments in the presence of aluminium ions which can be taken up into hyperaccumulating plants.