Lycopodium powder is a yellow-tan dust-like powder historically used as a flash powder

Flash powder

Flash powder is a pyrotechnic composition, a mixture of oxidizer and metallic fuel, which burns quickly and if confined produces a loud report. It is widely used in theatrical pyrotechnics and fireworks and was once used for flashes in photography.Different varieties of flash powder are made from...

. It is composed of the dry spore

Spore

In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...

s of clubmoss plants, various fern relatives

Pteridophyte

The pteridophytes are vascular plants that produce neither flowers nor seeds, and are hence called vascular cryptogams. Instead, they reproduce and disperse only via spores. Pteridophytes include horsetails, ferns, club mosses, and quillworts...

 principally in the genera Lycopodium

Lycopodium

Lycopodium is a genus of clubmosses, also known as ground pines or creeping cedar, in the family Lycopodiaceae, a family of fern-allies...

and Diphasiastrum

Diphasiastrum

Diphasiastrum is a genus of clubmosses in the plant family Lycopodiaceae. It is closely related to the genus Lycopodium, and some botanists treat it within a broad view of that genus as a section, Lycopodium sect. Complanata...

. When mixed with air, the spores are highly flammable because of their high fat

Fat

Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...

 content and their large surface area per unit of volume — a single spore's diameter is about 33 micrometers (μm)

Micrometre

A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...

, requiring about 30 laid side by side to span a millimeter, or 750 to span an inch. Preferred source species are Lycopodium clavatum (wolf's-foot clubmoss)

Lycopodium clavatum

Lycopodium clavatum is the most widespread species in the genus Lycopodium of the clubmoss family Lycopodiaceae....

 and Diphasiastrum digitatum (common groundcedar)

Diphasiastrum digitatum

Diphasiastrum digitatum is most commonly known as Groundcedar, along with other members of its genus, but the common name Fan Clubmoss can be used to refer to it specifically. It is the most common species of Diphasiastrum in North America. It is a type of plant known as a clubmoss, which is...

 because these widespread and often locally abundant species are both prolific in their spore production and easy to collect.

The principal early use of lycopodium powder was in photography

Photography

Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...

, to provide the extra light needed for portraits and other low-light photography before the invention of flash bulb

Flash (photography)

A flash is a device used in photography producing a flash of artificial light at a color temperature of about 5500 K to help illuminate a scene. A major purpose of a flash is to illuminate a dark scene. Other uses are capturing quickly moving objects or changing the quality of light...

s. It has also been used in fireworks

Fireworks

Fireworks are a class of explosive pyrotechnic devices used for aesthetic and entertainment purposes. The most common use of a firework is as part of a fireworks display. A fireworks event is a display of the effects produced by firework devices...

 and explosives, fingerprint powder

Fingerprint powder

Fingerprint powders are fine powders used in dusting for fingerprints by crime scene investigators and others in law enforcement. The process of dusting for fingerprints involves various methods intended to get the particles of the powder to adhere to residue left by friction ridge skin on the...

s, as a covering for pill

Pill

Pill or The Pill may refer to:* Pill , referring to anything small and round for a specific dose of medicine. The term is used colloquially in several ways:** A tablet or capsule which replaced dosing via pill...

s, and as an ice cream

Ice cream

Ice cream is a frozen dessert usually made from dairy products, such as milk and cream, and often combined with fruits or other ingredients and flavours. Most varieties contain sugar, although some are made with other sweeteners...

 stabilizer. Today, the principal use of the powder is to create flashes or flames that are large and impressive but relatively easy to manage safely in magic

Magic (paranormal)

Magic is the claimed art of manipulating aspects of reality either by supernatural means or through knowledge of occult laws unknown to science. It is in contrast to science, in that science does not accept anything not subject to either direct or indirect observation, and subject to logical...

 acts and for cinema and theatrical special effects. Lycopodium powder is also sometimes used as a lubricating dust on skin-contacting latex (natural rubber) goods, such as condom

Condom

A condom is a barrier device most commonly used during sexual intercourse to reduce the probability of pregnancy and spreading sexually transmitted diseases . It is put on a man's erect penis and physically blocks ejaculated semen from entering the body of a sexual partner...

s and medical gloves

Medical gloves

Medical gloves are disposable gloves used during medical examinations and procedures that help prevent contamination between caregivers and patients. Medical gloves are made of different polymers including latex, nitrile rubber, vinyl and neoprene; they come unpowdered, or powdered with cornstarch...

.

In physics

Physics

Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

 experiments and demonstrations, lycopoidum powder is used to make sound waves in air visible for observation and measurement, and to make a pattern of electrostatic charge visible. If the surface of a cup of water is coated with lycopodium powder, a finger or other object inserted straight into the cup will come out dusted with the powder but remain perfectly dry.

As a then-common laboratory supply, lycopodium powder was often used by inventors developing experimental prototypes. For example, Nicéphore Niépce

Nicéphore Niépce

Nicéphore Niépce March 7, 1765 – July 5, 1833) was a French inventor, most noted as one of the inventors of photography and a pioneer in the field.He is most noted for producing the world's first known photograph in 1825...

 used lycopodium powder in the fuel for the first internal combustion engine, the Pyréolophore

Pyréolophore

The Pyréolophore was probably the world's first internal combustion engine. It was invented in the early 19th century in Chalon-sur-Saône, France, by the Niépce brothers: Nicéphore Niépce and his brother Claude....

, about 1807, and Chester Carlson

Chester Carlson

Chester Floyd Carlson was an American physicist, inventor, and patent attorney born in Seattle, Washington....

 used lycopodium powder in 1938 in his early experiments to demonstrate xerography

Xerography

Xerography is a dry photocopying technique invented by Chester Carlson in 1938, for which he was awarded on October 6, 1942. Carlson originally called his invention electrophotography...

.