page_title: Hydnellum ferrugineum
section_title: Description
hierarchical_section_title: Hydnellum ferrugineum / Description
caption_attribution_description: English: A fruit body of the stipitate hydnoid fungus Hydnellum ferrugineum. Specimen photographed in Perote, Veracruz, Mexico.
context_page_description: Hydnellum ferrugineum, commonly known as the mealy tooth or the reddish-brown corky spine fungus, is a species of tooth fungus in the family Bankeraceae. A widely distributed species, it is found in north Africa, Asia, Europe, and North America. The fungus fruits on the ground singly or in clusters in conifer forest, usually in poor or sandy soil. Fruit bodies are somewhat top-shaped, measuring 3–10 cm in diameter. Their velvety surfaces, initially white to pink, sometimes exude drops of red liquid. The lower surface of the fruit body features white to reddish-brown spines up to 6 mm long. Mature fruit bodies become dark reddish brown in color, and are then difficult to distinguish from other similar Hydnellum species. H. ferrugineum forms a mat of mycelia in the humus and upper soil where it grows. The presence of the fungus changes the characteristics of the soil, making it more podzolized.
context_section_description: The fruit bodies of Hydnellum ferrugineum are more or less top-shaped with caps that are 3–10 cm (1.2–3.9 in) in diameter. They are at first convex, then pulvinate (cushion-shaped), later flattening or becoming slightly depressed in the center. The cap surface of young fruit bodies is uneven, with a velvety to felted texture, and a whitish to pink color. It sometimes exudes blood-red drops of fluid in the depressions. The surface later becomes flesh-colored to dark reddish brown, but with wavy margin remaining whitish. The lower surface of the fruit body bears the hymenium, the fertile spore-bearing tissue. It comprises a dense arrangement of white to reddish brown spines up to 6 mm long, hanging vertically downwards. The stout stipe measures 1–6 cm (0.4–2.4 in) long by 1–3 cm (0.4–1.2 in) thick, and is the same color as the cap. Fruit bodies have a "distinctly mealy" odor (similar to the smell of freshly ground flour), but are inedible.
  The flesh is reddish or purplish-brown with white flecks. Initially spongy and soft, it becomes tough and corky as the fruit body matures. In the stipe, the flesh can become blackish in age. Like other Hydnellum species, fruit body tissue is made of generative hyphae that do not expand. This slows the growth of the fruit body, often enabling it to persist for several months. The fungus employs an indeterminate growth pattern, in which the fruit body formation begins from a vertical column of hyphae that eventually expand at the top to form the cap. Any solid objects encountered during growth, such as grass or twigs, can be enveloped by the expanding fruit body. Similarly, closely neighboring caps can fuse together during growth.
  The broadly ellipsoid to roughly spherical spores are 5.5–7.5 by 4.5–5.5 μm. Their surfaces are covered with small rounded bumps. The basidia (spore-bearing cells) are narrowly club-shaped, four-spored, and measure 25–30 by 6–7.5 μm. The hyphae of the flesh are brownish with thin walls, and measure 4–6 μm; hyphae in the spines are thin-walled, septate, and sometimes branched, measuring 3.5–4.5 μm. The hyphae do not have clamp connections.
caption: Fruit bodies can envelop obstacles as they grow.
exif: {"Image Make": "Canon", "Image Model": "Canon EOS 60D", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Microsoft Windows Photo Viewer 6.1.7600.16385", "Image DateTime": "2011:10:07 09:32:50", "Image Artist": "", "Image YCbCrPositioning": "Co-sited", "Image Copyright": "", "Image ExifOffset": "2332", "Image Padding": "[]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "13226", "Thumbnail JPEGInterchangeFormatLength": "5869", "EXIF ExposureTime": "1/50", "EXIF FNumber": "20", "EXIF ExposureProgram": "Manual", "EXIF ISOSpeedRatings": "2500", "EXIF SensitivityType": "Recommended Exposure Index", "EXIF RecommendedExposureIndex": "2500", "EXIF ExifVersion": "0230", "EXIF DateTimeOriginal": "2011:10:05 10:21:20", "EXIF DateTimeDigitized": "2011:10:05 10:21:20", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ShutterSpeedValue": "45/8", "EXIF ApertureValue": "69/8", "EXIF ExposureBiasValue": "0", "EXIF MeteringMode": "Spot", "EXIF Flash": "Flash fired, compulsory flash mode", "EXIF FocalLength": "100", "EXIF SubSecTime": "89", "EXIF SubSecTimeOriginal": "89", "EXIF SubSecTimeDigitized": "89", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "3456", "EXIF ExifImageLength": "2304", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "12926", "EXIF FocalPlaneXResolution": "691200/181", "EXIF FocalPlaneYResolution": "460800/119", "EXIF FocalPlaneResolutionUnit": "2", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Manual Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard", "EXIF CameraOwnerName": "", "EXIF BodySerialNumber": "0470222664", "EXIF LensSpecification": "[100, 100, 0/0, 0/0]", "EXIF LensModel": "EF100mm f/2.8L Macro IS USM", "EXIF LensSerialNumber": "0000012e6a", "EXIF Padding": "[]", "EXIF OffsetSchema": "4068"}