A tubercle is generally a wart-like projection, but it has slightly different meaning depending on which family of plants or animals it is used to refer to.

In the case of certain orchids and cacti

Cactus

A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...

, it denotes a round nodule

Nodule (geology)

A nodule in petrology or mineralogy is a secondary structure, generally spherical or irregularly rounded in shape. Nodules are typically solid replacement bodies of chert or iron oxides formed during diagenesis of a sedimentary rock...

, small eminence

Eminence

-Anatomy:In anatomy, eminence implies a protuberance, and may refer to a variety of structures:*Collateral eminence, alongside the hippocampus in the brain*Cruciform eminence, in the occipital bone of the skull...

, or warty

Wart

A wart is generally a small, rough growth, typically on a human’s hands or feet but often other locations, that can resemble a cauliflower or a solid blister. They are caused by a viral infection, specifically by human papillomavirus 2 and 7. There are as many as 10 varieties of warts, the most...

 outgrowth found on the lip

Labellum

Labellum is the Latin diminutive of labium, meaning lip. These are anatomical terms used descriptively in biology, for example in Entomology and botany.-Botany:...

. They are also known as podaria (singular podarium). When referring to some members of the pea family

Fabaceae

The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...

, it is used to refer to the wart-like excrescences that are found on the roots.

In mycology

Mycology

Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans as a source for tinder, medicinals , food and entheogens, as well as their dangers, such as poisoning or...

, a tubercle is used to refer to a mass of hypha

Hypha

A hypha is a long, branching filamentous structure of a fungus, and also of unrelated Actinobacteria. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium; yeasts are unicellular fungi that do not grow as hyphae.-Structure:A hypha consists of one or...

e from which a mushroom

Mushroom

A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...

 is made.

When it is used in relation to certain dorid nudibranch

Nudibranch

A nudibranch is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, marine gastropod mollusks which shed their shell after their larval stage. They are noted for their often extraordinary colors and striking forms...

s such as Peltodoris nobilis

Peltodoris nobilis

Peltodoris nobilis, common names sea lemon, or the noble dorid, is a species of colorful sea slug, a dorid nudibranch, a shell-less marine gastropod mollusk in the family Discodorididae....

, it means the nodules on the dorsum of the animal.
These tubercles in nudibranchs can present themselves in different ways : each tubercle in a single rounded, conical or angular form, each tubercle in a compound form of two or more levels, tubercles in amalgamated clusters or as tubercles forming or joined by a ridge.

In dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s, a tubercle is a general term for the scales seen in skin impressions. In duck-billed dinosaurs

Hadrosaurid

Hadrosaurids or duck-billed dinosaurs are members of the family Hadrosauridae, and include ornithopods such as Edmontosaurus and Parasaurolophus. They were common herbivores in the Upper Cretaceous Period of what are now Asia, Europe and North America. They are descendants of the Upper...

, for example, three main types of tubercles are defined: small tubercles with no definite arrangement (ground tubercles); larger, polygon

Polygon

In geometry a polygon is a flat shape consisting of straight lines that are joined to form a closed chain orcircuit.A polygon is traditionally a plane figure that is bounded by a closed path, composed of a finite sequence of straight line segments...

al tubercles (pavement tubercles) up to 1 cm (0.4 in) in diameter, which are grouped into clusters separated by ground tubercles; and limpet

Limpet

Limpet is a common name for a number of different kinds of saltwater and freshwater snails ; it is applied to those snails that have a simple shell which is more or less conical in shape, and either is not spirally coiled, or appears not to be coiled in the adult snails.The name limpet is most...

-shaped conical scutes.

External links

Tubercle at Cactus-Art.biz