Campanula carpatha, not to be confused with C. carpatica which grows some distance away in the Carpathian Mountains, is an endemic of Karpathos. It inhabitats low altitude limestone cliffs and rocky areas growing in fairly shady crevices and forms tufts or clumps to 30 cm across of dark grey-green, thick, spathulate, sharply toothed, hairy leaves that are to 7.5 cm long. The stem leaves are usually shorter than the basal leaves. The tubular flowers are rich blue to violet blue, to 3.8 cm long with flared lobes and cover the whole plant. It was introduced into cultivation by Peter Davis in 1950 but was soon lost to cultivation. A reintroduction in 1983 by Helen and Ivor Barton has proved more successful and seed is often offered in seed exchanges. Although some authorities consider C. carpatha to be a synonym of C. tubulosa I feel there is a definite difference. Grow it in a warm spot or as a pot plant for exhibition. Propagate by cuttings or seed sown in autumn to spring. It tends to be short lived and is best kept going by seed.
Campanula carpatha var. ‘alba’ is much more difficult to grow and even more spectacular in flower. Large white flowers to 4 cm or more long are jam packed into the foliage making it a necessity to remove some of the buds on show plants so it can look its best. During its active growth water can be given quite freely but kept off the foliage. However over the winter period it is susceptible to botrytis unless all dead foliage is removed and as the foliage is quite brittle care must be when cleaning the plant as it can easily be broken accidentally. The plant must kept fairly dry during this time and if watered at all it is best to stand the pot in water not apply it adjacent to the foliage. I have never tried growing it outside as I am sure the damp winter will mean instant death. Cuttings taken from spring through summer easily root in damp sand, the only trouble being the difficulty in finding cutting material of sufficient length. My white flowering plants have never set seed.