While it is now commonly known as harebell or bluebell, it was historically known by several other names including blawort, hair-bell, lady's thimble, witch's bells, and witch's thimbles. Elsewhere in Britain, "bluebell" refers to Hyacinthoides non-scripta, and in North America, "bluebell" typically refers to species in the genus Mertensia, such as Mertensia virginica.
Description
Campanula rotundifolia is a perennial, slender, prostrate to erect herb, spreading by seed and rhizomes. The basal leaves are long-stalked, rounded to heart-shaped, usually slightly toothed, with prominent hydathodes, and often wither early. Leaves on the flowering stems are long and narrow and the upper ones are unstemmed. The inflorescence is a panicle or raceme, with 1 to many flowers borne on very slender pedicels. The flowers usually have five pale to mid violet-blue petals fused together into a bell shape, about long and five long, pointed green sepals behind them. Plants with pale pink or white flowers may also occur. The petal lobes are triangular and curve outwards. The seeds are produced in a capsule about diameter and are released by pores at the base of the capsule. Seedlings are minute, but established plants can compete with tall grass. As with many other Campanula species, all parts of the plant exude white latex when injured or broken. The flowering period is long and varies by location. In the British Isles, harebell flowers from July to November. In Missouri, it flowers from May to August; in Minnesota, from June to October. The flowers are pollinated by bees, but can self-pollinate.
Distribution and habitat
Campanula rotundifolia occurs from Spitzbergen, extending in mainland Europe from northernmost Scandinavia to the Pyrenees and the French Mediterranean coast. It also occurs on the southern coasts of Greenland, on Iceland and on southern Novaya Zemlya. It is not found in Canada. It occurs as tetraploid or hexaploid populations in Britain and Ireland, but diploids occur widely in continental Europe. In Britain, the tetraploid population has an easterly distribution and the hexaploid population a westerly distribution, and very little mixing occurs at the range boundaries. Harebells grow in dry, nutrient-poor grasslands and heaths. The plant often successfully colonises cracks in walls or cliff faces and stable dunes. C. rotundifolia is more inclined to occupy climates that have an average temperature below 0 °C in the cold months and above 10 °C in the summer.
