the cone tooth

Description:

The fruit body of A. vulgare is fibrous when fresh, and becomes stiff when dry. The cap is round or kidney-shaped, flat on one side and rounded on the other, and between 0.5 and 2 cm (0.2 and 0.8 in) in diameter—although it has been known to reach up to 4 cm (1.6 in). The surface is covered with bristles, but becomes smooth with maturity; it is initially dark chestnut-brown but can become almost black as it ages. The cap margin, usually lighter in color than the center, becomes rolled inward in maturity and often wavy. The color of the cap margin is buff to light brown, roughly the same color as the spines. The spines on the underside of the cap are up to 3 mm (0.12 in) long, cylindrical down to the base with sharp tips. They are white to light brown when young, later covered with a white spore mass and then ashy gray. Auriscalpium vulgare usually has a single stem, but occasionally several stems arise from a thick common base. The stem is 14–55 mm (0.55–2.2 in) long, by 1–2 mm (0.04–0.08 in) thick. It is attached to the side of the cap, and cylindrical or slightly flattened with a bulbous base. The surface is covered with hairy fibers (especially near the base), and is a dark chestnut-brown color. The flesh is up to 0.5 mm thick, and composed of two distinct layers. The upper compact cortical layer is thin, black-brown, and covered with hairs. The lower layer is thick, soft, white to light brown, and made of thin, thread-like filaments arranged in a roughly parallel fashion. Similarly, the stem is layered, with a thin dark cortical layer covered by hairs, which encircles the inner ochraceous-colored flesh. A drop of potassium hydroxide applied to the surface of the mushroom will cause it to instantly stain black

Habitat:

Auriscalpium vulgare is a saprobic species. The fruit bodies grow solitarily or clustered on fallen pine cones, especially those that are buried or partially buried. It especially prefers Scots Pine (Pinus sylvestris), but has also been reported to occur on spruce cones. In the California area, it grows primarily on Douglas-fir cones. One author noted finding the mushroom on spruce needles on top of squirrel dens where cone bracts were present in the duff. In a Chinese study conducted in the Laojun Mountain region, southwestern China, A. vulgare was found to be one of the most dominant species collected from mixed forest at an altitude of 2,600–3,000 m (8,500–9,800 ft). A study on the effect of slash and burn practices for jhum cultivation in northeast India showed that the fungus prefers to fruit on burned cones of the Khasi Pine, and that the number of fruit bodies on unburned cones increases with increased girth size of the cone. The fungus is widely distributed in Europe, Central America, North America, temperate Asia, and Turkey. In North America, its range extends north from Canada south to the Trans-Mexican Volcanic Belt south of Mexico City. The mushroom is common, appearing in the summer and autumn, although it is easily overlooked because of its small size and nondescript coloration

Notes:

Growth in culture Auriscalpium vulgare can be grown in pure culture on agar-containing plates supplemented with nutrients. The colonies that grow are white to pale cream color, and cover the agar surface within six weeks from the initial inoculation. The growth is made of hyphae that are bent-over, and do not form aerial hyphae (hyphae that extend above the surface of the agar). Typically, two indistinct zones develop at about 6 mm (0.24 in) and 15 millimetres (0.59 in) from the initial inoculum spot, with each zone 3–4 mm (0.12–0.16 in) wide. The zones appears somewhat lighter in color because the hyphae are more closely packed and form crystalline substances that deposit into the agar. The advancing edge of the mycelia is composed of two types of hyphae. The first are submerged into the agar, measuring 0.8–1.5 µm in diameter. They are thin-walled, hyaline, clamped, long-celled, and branched at nearly 90°. The second are the surface hyphae: they are straight to occasionally somewhat spiral (subhelicoid), thin-walled, clamped, branched acutely, usually with a clamp at the branch base, and measure 1.8–3.0 µm diameter. In addition, there are frequently "empty" hyphae that are short-celled, and occasionally clamped. Gloeocystidia (thin-walled cystidia with refractive, frequently granular contents) are rare. The mature mycelium consists of thin-walled, densely packed, vegetative hyphae that are 1.5–3.2 µm in diameter. They are short-celled, clamped, often gnarled or subhelicoid, frequently branched at about 45°, with a clamp at base of the branch. Their contents are somewhat granular to packed with amorphous granules that appear refractive when viewed under phase contrast microscopy. Their walls are often encrusted with tiny granules. Gloeocystidia are common; they measure 50–85 by 6.5–8.5 µm, and are club-shaped (sometimes elongated), thin-walled, and often have one or two lobes with rounded apices. Their contents are foamy and pale yellow, they appear yellow-refractive under phase contrast. Initially they are erect but they soon fall under their own weight to lie on agar surface. Crystalline deposits are abundant as small plate-like or star-like, randomly scattered crystals. Fruiting begins about six weeks after the initial inoculation on the agar plate, but only when portions of fruit bodies (teeth or stem sections) are used as the inoculum to initiate growth; the use of vegetative mycelium as inoculum precludes subsequent fruiting. Mature fruit bodies grow very close to the initial site of inoculation—within 3 mm (0.12 in)—and take about 60 days to mature after they first start to form .