AT A GLANCE
Common Name: Haast’s Blue Mushroom
Scientific Name: Entoloma haastii
Category: Fungi
Subcategory: Mushrooms
Size: Cap diameter: 0.8–2.0 in (2.0–5.0 cm); Stipe height: 1.6–3.5 in (4–9 cm)
Weight: Hydrated biomass: 0.3–0.7 oz (10–20 g)
Lifespan: Fruiting body: 3–7 days; Perennial subterranean mycelium
Diet: Saprotroph (decomposes damp leaf litter, moss beds, and forest humus)
Habitat: Temperate southern beech forests and mossy podocarp gullies
Range: Endemic to New Zealand (North and South Islands)
Conservation Status: Least Concern (IUCN Red List)

Overview

Haast’s Blue Mushroom (Entoloma haastii) is a breathtaking, brightly colored agaric fungus endemic to the pristine temperate rainforests of New Zealand. Named in honor of German geologist Sir Julius von Haast, this species is renowned for its intense indigo-to-cobalt blue coloration, glowing like a sapphire amid lush emerald bryophyte moss beds on southern beech forest floors.

Biology and Physical Characteristics

Entoloma haastii features a conical-to-campanulate cap that expands with age, displaying a vibrant, non-fading cobalt-blue hue. Its stipe is slender, fibrous, and similarly rich blue, often adorned with fine white basal mycelium. Uniquely for the genus Entoloma, its gills start bluish-white but transition to a soft salmon-pink as the distinctive angular, multi-sided pink spores mature.

Behavior and Ecology

Operating as a saprotrophic decomposer, Entoloma haastii breaks down organic cellulose and lignin within deep podocarp and beech leaf humus. It fruits primarily during late summer and autumn rains (March to May in the Southern Hemisphere), emerging in scattered troops along moist valley floors and stream margins.

Conservation and Human Impact

Evaluated as Least Concern by the IUCN, Entoloma haastii is well-represented throughout New Zealand’s protected national parks, including Fiordland, Kahurangi, and Tongariro. Preserving continuous canopy moisture is essential for safeguarding delicate mycelial networks against microclimatic drying.

Interesting Factoid

While almost all blue pigments in nature fade quickly upon maturity, Haast’s Blue Mushroom retains its intense electric cobalt-blue coloration through the synthesis of unusual azulene-like fungal pigments!

Last updated: October 2026