There is a finegroup of purple lace caps at the Henrietta Street entrance to the park and a couple of places elsewhere. It is native to the Himalayas and southern China, and is characterised by large softly hispid leaves. Hundreds of horticultural varieties of Hydrangeas have been produced. The colour change between pink ( ph>7 ) and blue ( pH < 7 ) in Hydrangeas is related to the availability of aluminium ions in the soil and therefore will not apply to plants grown in potting compost.
