''Desmodium'' 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 ...

of plants in the legume family

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

, sometimes called tick-trefoil, tick clover, hitch hikers or beggar lice. There are dozens of

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

and the delimitation of the genus has shifted much over time. Species are distributed widely – from Quebec to northern Argentina in the Americas, across northern and southern tropical Africa, in the southern Arabian Peninsula, in Myanmar and Thailand, New Guinea, and northern and eastern Australia.

Description

These are mostly inconspicuous plants; few have bright or large flowers. Though some can become sizeable plants, most are

herb Herbs are a widely distributed and widespread group of plants, excluding vegetables, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal purposes, or for fragrances. Culinary use typically distingu ...

s or small

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

s. Their fruit are

loment A loment (or lomentum) is a part of certain legume plants. It is a type of dehiscent fruit that breaks apart at the constrictions occurring between segments, so that each segment contains only one seed. It is a type of schizocarp. Tick trefoil ('' ...

s, meaning each

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

is dispersed individually enclosed in its segment. This makes them tenacious plants and some species are considered

weed A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. Pla ...

s in places.

Uses

Several ''Desmodium'' species release organic compounds, aerially and into the soil, which make them useful for agriculture:

Allelopathic Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the germination, growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have ben ...

compounds are used there via push-pull technology. For this ''Desmodium heterocarpon'' (now '' Grona heterocarpos''), ''

Desmodium intortum ''Desmodium intortum'', known as greenleaf desmodium and also as beggarlice along with other members of its genus, is a species of flowering plant in the genus ''Desmodium'', native to Mexico, Central America, northern South America, the Galápag ...

'', and ''

Desmodium uncinatum ''Desmodium uncinatum'', the silverleaf desmodium, is a species of flowering plant in the family Fabaceae, native to Latin America, and introduced as a fodder Fodder (), also called provender (), is any agriculture, agricultural foodstuff u ...

'' are inter-cropped in

maize Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native American ...

and

sorghum ''Sorghum bicolor'', commonly called sorghum () and also known as great millet, broomcorn, guinea corn, durra, imphee, jowar, or milo, is a species in the Poaceae, grass genus ''Sorghum (genus), Sorghum'' cultivated for its grain. The grain i ...

fields to suppress witchweeds, including Asiatic witchweed (''Striga asiatica'') and purple witchweed (''S. hermonthica'') and to repel ''

Chilo partellus ''Chilo partellus'', the spotted stalk borer or spotted stem borer, is a moth in the family Crambidae. It was described by Charles Swinhoe in 1885. It is found in India, Pakistan, Iran, Ethiopia, Lesotho, Madagascar, Malawi, South Africa, Sudan, T ...

'', a stem-boring

grass moth Crambidae comprises the grass moth family of lepidopterans. They are variable in appearance, with the nominal subfamily Crambinae (grass moths) taking up closely folded postures on grass stems where they are inconspicuous, while other subfamilies ...

Insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s (including pests) are likewise repelled by high amounts of antixenotic

allomone An allomone (from Ancient Greek ' "other" and pheromone) is a type of semiochemical produced and released by an individual of one species that affects the behaviour of a member of another species to the benefit of the originator but not the rec ...

s produced by ''Desmodium''. A blue dye is obtained from ''

Desmodium incanum :''The ''Desmodium incanum'' of many older sources is actually '' Desmodium laxiflorum''; see below.'' ''Desmodium incanum'', also known as creeping beggarweed, Spanish clover, Spanish tick-trefoil or hitchhikers is a perennial plant native to ...

''. Tick-trefoils in agriculture can also be used as

living mulch In agriculture, a living mulch is a cover crop interplanted or undersown with a main crop, and intended to serve the purposes of a mulch, such as weed suppression and regulation of soil temperature. Living mulches grow for a long time with the ma ...

and as

green manure In agriculture, a green manure is a crop specifically cultivated to be incorporated into the soil while still green. Typically, the green manure's Biomass (ecology), biomass is incorporated with a plow or disk, as is often done with (brown) man ...

, as they improve soil fertility via

nitrogen fixation Nitrogen fixation is a chemical process by which molecular dinitrogen () is converted into ammonia (). It occurs both biologically and abiological nitrogen fixation, abiologically in chemical industry, chemical industries. Biological nitrogen ...

. Most also make good

fodder Fodder (), also called provender (), is any agriculture, agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, domestic rabbit, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food ...

for animals including

bobwhite ''Colinus'' is a genus of birds in the New World quail family, Odontophoridae. Members of the genus are commonly known as bobwhites. Taxonomy The genus ''Colinus'' was introduced in 1820 by the German naturalist Georg August Goldfuss to accommo ...

, turkey,

grouse Grouse are a group of birds from the order (biology), order Galliformes, in the family (biology), family Phasianidae. Grouse are presently assigned to the Tribe (biology), tribe Tetraonini (formerly the subfamily Tetraoninae and the family Tetr ...

, deer, cattle and goats. Wild-living, non-farmed deer appear to rely on ''Desmodium'' species in certain areas, particularly during the more stressful summer months. The

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder ...

s of the lesser grass blue (''Zizina otis'') and the

two-barred flasher ''Telegonus fulgerator'', the two-barred flasher, is a species of spread-wing skipper butterfly in the family Hesperiidae which may constitute a possible cryptic species complex. It ranges all over the Americas, from the southern United States ...

(''Astraptes fulgerator'') feed on tick-trefoils.

Alkaloids

Some ''Desmodium'' species have formerly been known to contain high amounts of

tryptamine Tryptamine is an indolamine metabolite of the essential amino acid tryptophan. The chemical structure is defined by an indole—a fused benzene and pyrrole ring, and a 2-aminoethyl group at the second carbon (third aromatic atom, with the firs ...

alkaloid Alkaloids are a broad class of natural product, naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large varie ...

s, but many of the tryptamine-containing species have since been transferred to other genera.

Taxonomy and systematics

The

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

and

systematics Systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: phylogenetic trees, phylogenies). Phy ...

of the many dozens of ''Desmodium''

are confusing and unresolved. Related genera such as '' Codariocalyx'', ''

Hylodesmum ''Hylodesmum'' is a genus of flowering plants in the family Fabaceae, sometimes called ticktrefoils or tick-trefoils. It is sometimes treated as part of ''Desmodium ''Desmodium'' is a genus of plants in the legume family Fabaceae, sometimes ca ...

'', ''

Lespedeza ''Lespedeza'' is a genus of some 45 species (including nothospecies) of flowering plants in the pea family (Fabaceae), commonly known as bush clovers or (particularly East Asian species) Japanese clovers (''hagi''). The genus is native to warm t ...

'', '' Ohwia'', and '' Phyllodium'' were and sometimes still are included in ''Desmodium''.ILDIS (2005) Taxonomic authorities commonly disagree about the naming and placement of species. For example, ''Desmodium spirale'' as described by

August Grisebach August Heinrich Rudolf Grisebach (; 17 April 18149 May 1879) was a German botanist and phytogeographer. Biography Grisebach studied at the Lyceum in Hanover, the cloister-school at Ilfeld, and the University of Göttingen. He graduated in me ...

might refer to a distinct species, but its validity is doubtful. The "''Desmodium spirale''" of other authorities may refer to '' D. neomexicanum'', '' D. ospriostreblum'', or '' D. procumbens''. Similarly, the plant originally described as ''D. podocarpum'' by A. P. de Candolle is '' Hylodesmum podocarpum'' today, but "''Desmodium podocarpum''" might also refer to '' D. hookerianum'' or '' Hylodesmum laxum'', depending on the taxonomic authority.

Selected species

Species include: Ougeinia dalbergioides Bra23

* '' Desmodium acanthocladum'' F.Muell. * '' Desmodium canadense'' (L.) DC. – showy tick-trefoil, Canadian tick-trefoil * '' Desmodium canescens'' (L.) DC. – hoary tick-trefoil * '' Desmodium ciliare'' (Muhl.) DC. – hairy small-leaved tick-trefoil * '' Desmodium cuspidatum'' (Muhl.) Loudon – toothed tick-trefoil, large-bracted tick-trefoil * '' Desmodium fernaldii'' * '' Desmodium glabellum'' (Michx.) DC. * ''Desmodium'' × ''humifusum'' (Muhl. ex Bigelow) Beck * ''

Desmodium illinoense ''Desmodium illinoense'', the Illinois ticktrefoil, is a flowering plant in the bean family (Fabaceae), native to the central United States and Ontario, Canada. Illinois ticktrefoil grows in sunny places, such as prairies and oak savannas of the ...

'' A.Gray – Illinois tick-trefoil * ''

'' (Sw.) DC. – creeping beggarweed, Spanish tick-trefoil, Kaimi clover * ''

'' Greenleaf desmodium, kuru vine, beggarlice, tick clovers * '' Desmodium lineatum'' (Michx.) DC. – linear-leaved tick-trefoil * '' Desmodium marilandicum'' (L.) DC. – smooth small-leaved tick-trefoil * '' Desmodium molliculum'' * '' Desmodium ospriostreblum'' Chiov. * '' Desmodium paniculatum'' (L.) DC. – panicled tick-trefoil * '' Desmodium perplexum'' B.G.Schub. – perplexed tick-trefoil * '' Desmodium rotundifolium'' DC. – round-leaved tick-trefoil, dollar leaf * '' Desmodium sessilifolium'' * '' Desmodium tortuosum'' * '' Desmodium triflorum'' (L.) DC. * '' Desmodium tweedyi'' Britton – Tweedy's tick-trefoil * ''

'' (Jacq.) DC.– silver-leaved tick-trefoil, silverleaf * '' Desmodium varians'' (Labill.) G.Don

Formerly placed here

* '' Codariocalyx motorius'' – telegraph plant (as ''D. gyrans'', ''D. motorium'', ''D. roylei'') * '' Dendrolobium triangulare'' (as ''D. Desmodium umbellatum'' Moritz.) * '' Dendrolobium umbellatum'' (as ''D. umbellatum'' (L.) Benth. ) * '' Grona heterocarpos'' (as ''D. heterocarpon'' (Michx.) DC.) * '' Hylodesmum laxum'' (as ''D. laxum'' DC.) ** ''Hylodesmum laxum'' ssp. ''laxum'' (as ''D. austro-japonense'', ''D. bambusetorum'', ''D. gardneri'' auct. ''non'' Benth., ''D. laxiflorum'' ''sensu'' Miq., ''D. laxum'' var. ''kiusianum'', ''D. laxum'' ssp. ''laxum'', ''D. podocarpum'' auct. ''non'' DC. ''non'' Hook. & Arn., ''D. podocarpum'' DC. var. ''gardneri'' ''sensu'' Bedd., ''D. podocarpum'' DC. var. ''laxum'') * '' Hylodesmum leptopus'' (as ''D. gardneri'' Benth., ''D. laxum'' auct. ''non'' DC., ''D. laxum'' ssp. ''leptopus'', ''D. leptopus'', ''D. tashiroi'') * '' Hylodesmum podocarpum'' (as ''D. podocarpum'' DC., ''D. podocarpum'' DC. var. ''indicum'', ''D. podocarpum'' DC. var. ''japonicum'') ** ''Hylodesmum podocarpum'' ssp. ''oxyphyllum'' (as ''D. fallax'' var. ''mandshuricum'', ''D. japonicum'', ''D. mandshuricum'', ''D. oxyphyllum'' DC., ''D. podocarpum'' DC. var. ''mandshuricum'', ''D. podocarpum'' DC. ssp./var. ''oxyphyllum'', ''D. podocarpum'' DC. var. ''polyphyllum'', ''D. podocarpum'' DC. var. ''typicum'', ''D. racemosum'') * ''

Lespedeza thunbergii ''Lespedeza thunbergii'' is a species of flowering plant in the legume family known by the common names Thunberg's bushclover, Thunberg's lespedeza, and shrub lespedeza. It is native to the eastern Himalayas, China, Korea, and Japan. This specie ...

'' (as ''D. formosum'', ''D. thunbergii'') Lespedeza thunbergii2

** ''Lespedeza thunbergii'' var. ''thunbergii'' (as ''D. penduliflorum'' Oudem.) * '' Maekawaea macrocarpa'' (as ''D. macrocarpum'') * '' Maekawaea rhytidophylla'' (as ''D. rhytidophyllum'') * '' Maekawaea tenax'' (as ''D. tenax'') * '' Ohwia caudata'' (as ''D. caudatum'') * '' Phyllodium pulchellum'' (as ''D. pulchellum'')

References

* (2005)
Genus ''Desmodium''
Version 10.01, November 2005. Retrieved 2007-DEC-17.

External links

* Trout, K. (2002)
Trout's Notes on the Genus ''Desmodium''.
Mydriatic Productions. Better Days Publishing. {{Authority control Forages Fabaceae genera Taxa named by Nicaise Auguste Desvaux