AT A GLANCE
Common Name: Redcoats Bladderwort
Scientific Name: Utricularia menziesii
Category: Plants
Subcategory: Carnivorous Plants
Size: Flower height: 2.5–3.5 in (6.0–9.0 cm); Flower diameter: 0.8–1.0 in (2.0–2.5 cm)
Weight: Rosette biomass: 0.04–0.08 oz (1.0–2.5 g) per tuber clump
Lifespan: 15–25+ years via perennial dormant subterranean corms
Diet: Carnivorous (subterranean protozoans, nematodes, rotifers, and micro-crustaceans caught via suction traps)
Habitat: Thin moss mats on granite inselbergs, seepage zones, and winter-wet peaty sands
Range: Coastal and subcoastal sandplains of Southwest Western Australia
Conservation Status: Least Concern (IUCN / Widespread across protected national parks in WA)

Overview

The Redcoats Bladderwort (Utricularia menziesii) is an iconic, miniature carnivorous perennial herb endemic to the ancient, nutrient-depleted landscapes of Southwest Western Australia. Renowned for producing vivid, fire-engine red blossoms that evoke the British soldiers’ uniforms of historical lore, this tiny botanical jewel forms spectacular flowering carpets across damp moss pads during the cool southern winter, surviving scorching summer droughts by retreating into underground resting tubers.

Biology and Physical Characteristics

Utricularia menziesii is unique among bladderworts for its brilliant, bright scarlet flower featuring a prominent, elongated down-curving spur and a broad, flaring lower petal lip. Beneath the emerald moss cushions lies an intricate subterranean stolon system studded with thousands of microscopic suction traps (bladders). Each bladder contains sensitive trigger hairs and an interior negative pressure mechanism that snaps open in less than a millisecond to vacuum in unsuspecting nematodes and protozoans when touched.

Behavior and Ecology

Operating in an extreme Mediterranean climate characterized by drenched winters and arid, scorching summers, Utricularia menziesii possesses an obligate tuberous dormancy cycle. As autumn rains saturate the moss cushions on massive granite outcrops, the plant sprouts delicate spoon-shaped green leaves and initiates flowering between June and September. By early summer, as seepage waters evaporate, the entire aboveground growth withers away, and the plant survives safely underground as a miniature, starch-filled corm.

Conservation and Human Impact

Currently evaluated as Least Concern, Utricularia menziesii is widely distributed across several well-managed national parks, including Torndirrup, Stirling Range, and Cape Le Grand National Parks. However, localized colonies on granite domes remain susceptible to trampling by hikers, invasive weed encroachment, and shifting rainfall patterns caused by prolonged regional drying trends in Western Australia.

Interesting Factoid

Unlike nearly all other bladderwort species which have yellow, purple, or white flowers pollinated by insects, the bright scarlet blossoms and deep nectar spurs of Redcoats are specifically adapted for pollination by miniature Western Australian honeyeater birds.

Last updated: October 2026