''Lycopodium'' (from

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

''lykos'', wolf and ''podion'', diminutive of ''pous'', foot) is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

clubmoss Lycopodiopsida is a class of vascular plants also known as lycopsids, lycopods, or lycophytes. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching stems bearing simple leaves ...

es, also known as ground pines or creeping cedars, in the family

Lycopodiaceae The Lycopodiaceae (class Lycopodiopsida, order Lycopodiales) are an old family of vascular plants, including all of the core clubmosses and firmosses, comprising 17 accepted genera and about 500 known species. This family originated about 380 mi ...

. Two very different circumscriptions of the genus are in use. In the

Pteridophyte Phylogeny Group The Pteridophyte Phylogeny Group (PPG) is an informal international group of systematic botanists who collaborate to establish on the classification of pteridophytes ( lycophytes and ferns) that reflects knowledge about plant relationships discove ...

classification of 2016 (PPG I), ''Lycopodium'' is one of nine genera in the subfamily

Lycopodioideae ''Lycopodioideae'' is a subfamily in the family Lycopodiaceae in the Pteridophyte Phylogeny Group classification of 2016 (PPG I). It is equivalent to a broad circumscription of the genus '' Lycopodium'' in other classifications. Like all lyco ...

, and has from nine to 15 species. In other classifications, the genus is equivalent to the whole of the subfamily, since it includes all of the other genera. More than 40 species are accepted.

Description

They are

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

less, vascular, terrestrial or

epiphytic An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

s, with widely branched, erect, prostrate, or creeping stems, with small, simple, needle-like or scale-like

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

that cover the stem and branches thickly. The stems usually creep along the ground, forking at intervals. The leaves contain a single, unbranched vascular strand, and are

microphyll In plant anatomy and evolution a microphyll (or lycophyll) is a type of plant leaf with one single, unbranched leaf vein. Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. In the classical concept of ...

s by definition. They are usually arranged in spirals. The kidney-shaped (reniform)

spore In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...

-cases (

sporangia A sporangium (from Late Latin, ; : sporangia) is an enclosure in which spores are formed. It can be composed of a unicellular organism, single cell or can be multicellular organism, multicellular. Virtually all plants, fungus, fungi, and many ot ...

) contain spores of one kind only, ( isosporous, homosporous), and are borne on the upper surface of the leaf blade of specialized leaves (sporophylls) arranged in a cone-like strobilus at the end of upright stems. Each sporangium contains numerous small spores. The club-shaped appearance of these fertile stems gives the clubmosses their common name. Lycopods reproduce asexually by spores. The plants have an underground sexual phase that produces

gamete A gamete ( ) is a Ploidy#Haploid and monoploid, haploid cell that fuses with another haploid cell during fertilization in organisms that Sexual reproduction, reproduce sexually. Gametes are an organism's reproductive cells, also referred to as s ...

s, and this alternates in the lifecycle with the spore-producing plant. The prothallium developed from the spore is a subterranean mass of tissue of considerable size, and bears both the male and female organs ( antheridia and archegonia). They are more commonly distributed vegetatively, though, through above- or below-ground

rhizomes In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

Taxonomy

The genus ''Lycopodium'' was first published by

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

in 1753. He placed it in the Musci (mosses) along with genera such as ''

Sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store water, since ...

'', and included species such as ''Lycopodium selaginoides'', now placed in the genus ''

Selaginella ''Selaginella'', also known as spikemosses or lesser clubmosses, is a genus of lycophyte. It is usually treated as the only genus in the family Selaginellaceae, with over 750 known species. This family is distinguished from Lycopodiaceae (th ...

'' in a different order from ''Lycopodium''. Different sources use substantially different circumscriptions of the genus. Traditionally, ''Lycopodium'' was considered to be the only extant genus in the family

, so includes all the species in the family, although sometimes excluding one placed in the monotypic genus '' Phylloglossum''. Other sources divide Lycopodiaceae species into three broadly defined genera, ''Lycopodium'', ''Huperzia'' (including ''Phylloglossum'') and ''Lycopodiella''. In this approach, ''Lycopodium''

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

has about 40 species. In the

classification of 2016 (PPG I), the broadly defined genus is equivalent to the subfamily

, and ''Lycopodium'' is one of 16 genera in the family Lycopodiaceae, with between 9 and 15 species.

Species

Using the narrow circumscription of ''Lycopodium'', in which it is one of nine genera in the subfamily Lycopodioideae, the ''Checklist of Ferns and Lycophytes of the World'' recognized the following species : *'' Lycopodium clavatum'' L. – stag's-horn clubmoss; subcosmopolitan *'' Lycopodium diaphanum'' (P.Beauv.) Sw. –

Tristan da Cunha Tristan da Cunha (), colloquially Tristan, is a remote group of volcano, volcanic islands in the South Atlantic Ocean. It is one of three constituent parts of the British Overseas Territories, British Overseas Territory of Saint Helena, Ascensi ...

*'' Lycopodium japonicum'' Thunb. – eastern Asia (Japan west and south to

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

and

Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...

) *'' Lycopodium lagopus'' (Laest. ex C.Hartm.) Zinserl. ex Kuzen. – circumpolar arctic and subarctic *'' Lycopodium papuanum'' Nessel – New Guinea *'' Lycopodium venustulum'' Gaudich. –

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

Western Samoa Samoa, officially the Independent State of Samoa and known until 1997 as Western Samoa, is an island country in Polynesia, part of Oceania, in the South Pacific Ocean. It consists of two main islands ( Savai'i and Upolu), two smaller, inhabit ...

, the

Society Islands The Society Islands ( , officially ; ) are an archipelago in the South Pacific Ocean that includes the major islands of Tahiti, Mo'orea, Moorea, Raiatea, Bora Bora and Huahine. Politically, they are part of French Polynesia, an overseas country ...

*'' Lycopodium vestitum'' Desv. ex Poir. – northwest South America (Andes)

Uses

The spores of ''Lycopodium'' species are harvested and are sold as lycopodium powder. ''Lycopodium '' sp. herb has been used in the traditional Austrian medicine internally as tea or externally as compresses for treatment of disorders of the locomotor system, skin, liver and bile, kidneys and urinary tract, infections, rheumatism, and gout, though claims of efficacy are unproven. It has also been used in some United States government chemical warfare test programs such as Operation Dew.

U.S. National Research Council The National Academies of Sciences, Engineering, and Medicine (NASEM), also known as the National Academies, is a Congressional charter, congressionally chartered organization that serves as the collective scientific national academy of the Uni ...

, Subcommittee on Zinc Cadmium Sulfide
''Toxicologic Assessment of the Army's Zinc Cadmium Sulfide Dispersion''
National Academies Press, 1997, pp. 44–77, . ''Lycopodium'' powder was also used to determine the molecular size of

oleic acid Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish due to the presence of impurities. In chemical terms, oleic acid is cl ...

References

External links

Burning ''Lycopodium'' Powder: Simulating a Grain Elevator Explosion
by Kevin A. Boudreaux {{Authority control Lycopodiaceae Lycophyte genera