AT A GLANCE
- Common Name: Common Butterwort
- Scientific Name: Pinguicula vulgaris
- Category: Plants
- Subcategory: Carnivorous Plants
- Range: Circumboreal distribution across northern and temperate regions of Europe, northern Asia, and North America (Canada and northern US)
- Habitat Type: Nutrient-poor, wet, acidic to alkaline environments including peat bogs, fens, wet mountain flushes, damp limestone seepages, and wet heaths
- IUCN Red List Status: Least Concern
- Lifespan: Perennial; individual plants live 5 to 10+ years
- Diet: Carnivorous/Autotrophic (photosynthetic, supplemented by capturing and digesting small insects such as gnats, midges, and springtails)
- Average Size/Weight: Rosette diameter 5 to 12 cm; flowering stem height 5 to 15 cm
- Key Defining Feature: Compact basal rosette of greasy, yellowish-green leaves with curled edges covered in microscopic glandular hairs that trap midges like biological flypaper, topped by violet orchid-like flowers
Overview
The Common Butterwort (Pinguicula vulgaris) is an enchanting, insectivorous perennial plant in the bladderwort family Lentibulariaceae, native to the damp, nutrient-deficient bogs and alpine seepages of the Northern Hemisphere. Taking its common name from the greasy, buttery feel of its pale yellowish-green leaves, this clever carnivore thrives in waterlogged habitats where soil nitrogen and phosphorus are virtually nonexistent. By turning its leaves into glistening, enzyme-coated sticky flypaper, it traps tiny insects to nourish its lovely, violet, orchid-like blooms.
Biology and Physical Characteristics
Pinguicula vulgaris forms a flat, ground-hugging basal rosette of five to nine fleshy, oblong-ovate leaves with distinctly inrolled margins. The upper leaf surface is densely studded with two specialized types of microscopic glands: stalked pedicellate glands that secrete sticky droplets of viscous mucilage that glisten like dew in the sun, and sessile glands embedded flat in the leaf tissue that secrete a potent cocktail of digestive enzymes, including proteases, nucleases, and phosphatases. In late spring and summer, a slender, leafless stalk arises from the center, bearing a solitary, two-lipped violet-purple flower with a slender nectar spur.
Behavior and Ecology
When a small gnat, mosquito, or springtail lands on the glistening leaf, it becomes hopelessly mired in the sticky mucilage. The struggling insect stimulates the leaf to produce additional digestive enzymes; in response to prolonged movement, the leaf margins slowly curl inward by a few millimeters to pool the digestive juices around the prey and prevent rain from washing the nutrients away. Once digested, the soluble nitrogen, amino acids, and phosphates are absorbed directly through the leaf cuticle. In autumn, the plant withdraws all nutrients into a tight, dormant winter bud called a hibernaculum, which rests on the soil surface under snow until spring.
Conservation and Human Impact
The Common Butterwort is classified as Least Concern on the IUCN Red List due to its vast circumboreal distribution. However, southern lowland populations in Central Europe and the United Kingdom have suffered serious local declines due to the drainage and peat cutting of wetlands, afforestation of upland flushes, and agricultural eutrophication.
Interesting Factoid
The sticky digestive enzymes of the Common Butterwort are so potent that traditional Scandinavian dairy holders historically poured warm milk over its leaves to curdle it into a thick, delicious cultured yogurt called tätmjölk.