Regal Black Tooth (Hydnellum regium)

🏷️ Description

Deep in the coniferous forests of western North America, a bizarre and beautiful mushroom reigns: the Regal Black Tooth 🍄. With its majestic rosette form, haunting violet-black hues, and spiky underbelly, Hydnellum regium looks more like a gothic sea creature than a forest fungus.

🧬 Taxonomy & Discovery: Belonging to the family Bankeraceae, this tooth fungus was described as new to science in 1964 by Canadian mycologist Kenneth A. Harrison. He discovered it in the pine and spruce forests of Oregon, Idaho, and Colorado, and it has since also been documented in Washington and British Columbia.

🍽️ Cap

Hydnellum regium forms massive, complex rosettes—some reaching up to (25 cm / 10 in) wide and (15 cm / 6 in) tall—comprised of fused individual caps.

• Color: Violaceous black, often with grayish-white to olive-brown margins as it ages.

• Surface: Zonate, with concentric ridges, a matted fibrillose texture, and striate margins.

• Shape: Initially convex, eventually forming imbricated (shingled) structures, sometimes funnel-shaped with proliferating discs.

🩸 Flesh

• Texture: Firm and brittle, especially in the cap.

• Color: Violaceous to dull tan at the base, with subtle zonation—“alizarine blue” and “sepia” tones in older specimens.

🦷 Teeth (Spines)

Unlike gilled mushrooms, this species features tooth-like spines beneath its cap:

• Length: (0.3–0.9 cm / 0.12–0.35 in)

• Color: Starts bluish-gray to violet, turns dusky brown or blackish blue with age or bruising.

• Arrangement: Very close together, irregularly decurrent, and often become tubercles near the margin.

🌳 Stem

• Size: (5–15 cm / 2–6 in) tall, (2.5–5 cm / 1–2 in) thick

• Shape: Stout, central, tapering, corky and brittle

• Color: Pinkish cinnamon or grayish brown, sometimes with orange-yellow mycelium cavities when sliced lengthwise

👃 Odor & Taste

• Odor: Ranges from fragrant and aromatic to pungent or even faintly farinaceous

• Taste: Usually slightly bitter or mealy, sometimes peppery, but not distinct in many samples

🔬 Microscopic Features

• Spore print: Brown

• Spores: Round to oblong, (4.5–6 x 3.5–4.5 μm), tuberculate (bumpy)

• Basidia: 4-spored, 30–35 x 7–8 μm

• Hyphae: 1) Dark bluish with internal granules (cap); 2) Light-colored with external amber granules (stem)

• Reactivity: In KOH, cap hyphae turn dark green to black, granules dissolve; in Melzer's, dark hyphae become more distinct

🌲 Habitat & Distribution

This majestic fungus fruits singly or in fused groups on the forest floor beneath pine and spruce, favoring the Pacific Northwest but also appearing in parts of the Rocky Mountains. It’s more common along the Pacific Coast and uncommon at higher elevations.

⚠️ Edibility

Not considered edible due to its bitter taste and tough, corky texture—but it’s a real treat for the eyes!

🌟 Final Thoughts

With its towering, dark violet rosettes and glistening teeth, the Regal Black Tooth lives up to its noble name. A marvel of form and color, this forest gem reminds us that mushrooms are not only for food—but also for wonder. 👑🍄✨

Photo source: Alan Rockefeller (CC BY-SA 4.0)