A tubercle's generally a wart-like projection, but it's slightly different meaning depending on which family of plants or animals it's used to refer to. In the case of certain orchids and cacti, it denotes a round nodule, small eminence, or warty outgrowth found on the lip. They're also known as podaria, which's podaria in its plural form. When referring to some members of the pea family, it's used to refer to the wart-like excrescences that're found on the roots. In mycology, a tubercle's use… (More on Tubercle)