in the family Bankeraceae. Analyses of the ITS region by Parfitt and colleagues and Ainsworth and colleagues, have further revealed multiple cryptic lineages within the genus. Most of the cryptic species belong to the H. concrescens/H. scrobiculatum species complex, resulting in frequent misinterpretations of these old and widely applied names. At the moment, the number of phylogenetically distinct lineages confirmed by molecular sequencing exceeds the number of described taxa in the genus, making further taxonomic revisions inevitable in the future. Morphology Hydnellum fruitbodies have caps and stipes, often with indeterminant growth forms, that may grow in spurts and decay over several weeks. Neighboring fruitbodies can coalesce, forming intricately intertwined caps and partially fused stipes. The flesh has a zoned appearance and is fibrous when fresh, but becomes hard and woody when dry. Zones in the flesh reflect differences in growth during periods of low daytime and high nighttime humidity, and give a fairly accurate record of daily growth. The spines are crowded closely together and are typically decurrent (extending down the length of the stipe). Fruitbodies may display a variety of colors, from white to yellow, olive green, shades of orange, light brown, or dark brown in age. Spores of Hydnellum are almost spherical to oblong and tuberculate, and are brown in mass. The basidia (spore-bearing cells) are narrowly club-shaped and usually four-spored; there are no cystidia in Hydnellum. Three types of hyphae are found in the flesh of Hydnellum: generative hyphae (thin-walled, not inflated); skeletal hyphae (thick-walled and narrow); and thin-walled gloeoplerous-like hyphae, which stain with methyl blue. In conditions of high humidity, several species can form striking colored drops on the actively growing caps: red drops in H. peckii, H. diabolus, H. ferrugineum, and H. cruentum, yellow drops in H. caeruleum, and coffee-colored drops in H. mirabile. The common names of H. peckii reflect its appearance: "strawberries and cream" and "bleeding tooth fungus". Some Hydnellum species have a mealy odor (e.g. H. mirabile and H. pineticola) similar to freshly ground flour. H. zonatum smells like melilot, while H. suaveolens has a sweet odor resembling anise or peppermint. All are too tough and woody to be edible, and many have an acrid taste anyway. Differences between Hydnellum species tend to be more distinguishable in younger specimens. Fruitbody development is greatly influenced by environmental factors such as levels of rainfall, drying winds, and temperature. The blue tooth (H. caeruleum), for