Common butterwort

Buttery leaves that catch insects

The common butterwort is a small perennial carnivorous plant of the family Lentibulariaceae. It forms a flat rosette of yellow-green leaves, glossy and slightly greasy to the touch, hence its name (from the Latin pinguis, "fat"). The leaf surface is covered in tiny glandular hairs that secrete a viscous fluid: when a small insect lands on it, it becomes trapped and is digested. In summer the plant produces elegant solitary violet-blue flowers on a slender stalk.

Habitat and range

It is widespread across much of the northern hemisphere, in Europe, Asia and North America. It grows in damp, nutrient-poor places: bogs, wet meadows, banks and dripping rocks, often in the mountains. It is precisely the poverty of the soil that has driven it to supplement its diet by catching insects.

How it catches prey

The leaves act as a sticky trap: insects that land on them are held by the mucilage, and the plant curls its leaf edges slightly to increase contact and aid digestion. The enzymes it secretes dissolve the prey's tissues, from which it absorbs nitrogen and other nutrients scarce in the soil.

Cultivation

It can be grown by enthusiasts but needs specific care: a poor, acidic, lime-free mix kept always moist, and watering with rainwater or deionised water only, preferably from below. It loves bright light. In winter many temperate forms go dormant, shrinking to a compact winter bud called a hibernaculum.

Conservation

The species is listed as Least Concern but, like many bog plants, it suffers from the drainage and reclamation of wetlands. It should never be collected from the wild.