Cirsium rivulare 'Trevor's Blue Wonder' - 9cm pot Cirsium rivulare Trevor's Blue Wonder - 9cm pot Cirsium rivulare Trevor's Blue Wonder - 9cm pot £3.50 Sorry, this plant is currently out of stock. Purple-blue thistle flowers in spring and summer, held above silvery-green leaves. Not spiny or invasive. Sun, humus-rich soil. H: 1mSimilar to Cirsium rivulare 'Atropurpureum', but with slightly more purple in the flower colour.