Utricularia resupinata
Utricularia resupinata
Table of Contents
Use only distilled water, reverse osmosis (RO), or rainwater — ideally under 50 ppm TDS. Tap water, bottled mineral water, and softened water contain calcium, magnesium, and sodium that accumulate in the substrate and kill carnivorous plants within weeks. This is the #1 cause of cultivation failure.
Introduction & Discovery
Utricularia resupinata is a small, semi-aquatic bladderwort native to the eastern United States and parts of eastern Canada, producing delicate purple flowers that emerge from shallow water or wet sand at the margins of ponds and lakes. The specific name resupinata, meaning resupinate or inverted, refers to the unusual orientation of the flowers, which appear to be upside down compared to typical bladderwort flowers. This distinctive floral presentation gives the species a charming quirkiness that endears it to those who encounter it. U. resupinata grows partially submerged in the sandy or peaty shallows of oligotrophic lakes, bog ponds, and seasonal pools, with its stolons buried in the substrate and its tiny purple flowers just breaking the water surface or standing on the wet sand. The species is often overlooked in the field due to its diminutive size and its tendency to grow in habitats where it blends with the surrounding vegetation and substrate. For the grower, U. resupinata offers an unusual North American bladderwort that bridges the terrestrial and aquatic lifestyles, requiring wet, sandy conditions and full sun. Its purple flowers, though tiny, are a delightful sight when they appear above the substrate during summer.
Discovery & Naming
Described by B.D. Greene ex Bigelow in 1829 from specimens in the northeastern United States. Peter Taylor's 1989 monograph placed it in section Lecticula. The species' distribution extends from eastern Canada south to the Gulf Coast states, always in sandy or peaty lake and pond margins.
Trapping Mechanism
Small bladder traps on subterranean stolons, operating in waterlogged sandy substrate. Standard suction mechanism. Captures soil and benthic microorganisms.
Native Range & Distribution Map
Distribution map showing the native range of Utricularia resupinata.
Biology & Trapping Mechanism
Semi-aquatic perennial with stolons in wet sandy substrate bearing traps and small leaf-like organs. Flowers small, purple, resupinate in orientation, on very short scapes just above the substrate surface or water line. Winter dormancy in cold climates.
Prey & Feeding Ecology
Captures protozoa, nematodes, rotifers, and other microorganisms in the saturated sandy substrate of pond and lake margins.
Comparison with Similar Species
Unique among North American bladderworts for its resupinate flowers and semi-aquatic shoreline habitat. Distinguished from all other native species by flower orientation and growth habit.
Reproduction & Propagation
Stolon division in the active growing season. Seed sown on moist sand.
Cultivation & Substrate
Grow in pure sand or sand and peat mix, maintained waterlogged with the water level at or just above the substrate surface. Full sun. Cool to warm temperatures. Cold winter dormancy required.
Substrate: Live sphagnum, peat + sand, or aquatic
Water: Distilled / Rainwater only — NEVER tap water
Light: Bright indirect to full sun
Humidity: 60-95%
Common Mistakes to Avoid
Insufficient light. Allowing substrate to dry. Water too deep, submerging the plant. Failing to provide winter dormancy.
Seasonal Considerations
Spring: resume growth from dormancy. Summer: active growth and flowering. Autumn: prepare for dormancy. Winter: cold dormancy in moist, cold conditions.
Seasonal Care Calendar
🌱 Spring (Mar-May)
Water: Moderate
Feeding: No feeding
Monitor growth and adjust care as needed.
☀️ Summer (Jun-Aug)
Water: Moderate
Feeding: No feeding
Monitor growth and adjust care as needed.
🍂 Autumn (Sep-Nov)
Water: Moderate
Feeding: No feeding
Monitor growth and adjust care as needed.
❄️ Winter (Dec-Feb)
Water: Moderate
Feeding: No feeding
Monitor growth and adjust care as needed.
Diseases & Pests
Generally disease-free. Algal growth on substrate surface is the main issue.
Indoor Growing & Terrariums
Challenging indoors. Requires strong lighting and cold dormancy. A shallow tray of wet sand under LED lighting for the growing season, with cold storage for winter.
Terrarium Setup
A shallow tray of wet sand under bright lighting simulates the natural shoreline habitat. Unusual but effective display method.
Landscape & Bog Garden Use
Depending on climate, Utricularia resupinata may be grown outdoors in a bog garden or container water tray during the growing season.
Conservation & Collector Notes
Declining in parts of its range due to shoreline development, water level manipulation, and eutrophication. Listed as threatened in several states.
Collector Notes
An unusual species bridging terrestrial and aquatic lifestyles. The resupinate flowers are a unique curiosity. Uncommon in cultivation but available from specialist sources.
Ethnobotany & Cultural Significance
The lake and pond habitats of eastern North America are valued by indigenous communities for their ecological and cultural significance.
Frequently Asked Questions
What does 'resupinate' mean?
Resupinate means inverted or upside-down. The flowers appear to be oriented differently from typical bladderwort flowers, giving them a distinctive appearance.
Is it aquatic or terrestrial?
It is semi-aquatic, growing in the transition zone between land and water at pond and lake margins. The stolons are in saturated sand while flowers emerge just above the water line.
Is it difficult to grow?
Moderately challenging. It requires specific conditions: waterlogged sandy substrate, bright light, and cold dormancy.
How big are the flowers?
Very small, typically 5-10mm, but the purple color and unusual orientation make them interesting.
Where can I find it in the wild?
Look at the sandy margins of acid lakes and ponds in the eastern United States during summer. The tiny purple flowers just above the waterline or wet sand are the key identification feature.
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Quick Reference Summary: Utricularia resupinata
Golden Rule: Pure water, poor soil, maximum light. If you remember nothing else, remember this.
Utricularia resupinata is a small semi-aquatic bladderwort from eastern North America, producing distinctive resupinate purple flowers at the margins of acid lakes and ponds where its stolons thread through waterlogged sandy substrate. Requiring bright light, saturated sandy growing medium, and cold winter dormancy, it bridges the terrestrial and aquatic bladderwort lifestyles. This uncommon species adds a unique curiosity to collections focused on North American carnivorous plants.