Desmodium incanum
(creeping beggerweed)

Preferred Common Name

• creeping beggerweed

Other Scientific Names

• Aeschynomene incana (SW.) G. Mey.
• Aeschynomene spicata Poir.
• Desmodium canum (J.F. Gmel.) Schinz & Thell.
• Desmodium frutescens Schindl.
• Desmodium frutescens var. amblyophyllum (Urb.) Schindl.
• Desmodium incanum var. supinum (DC.) Hooker & Arnott
• Desmodium portoricense (Spreng.) G.Don
• Desmodium supinum (Sw.) DC.
• Desmodium supinum var. amblyophyllum Urb.
• Hedysarum canescens Mill.
• Hedysarum canum J.F. Gmel.
• Hedysarum incanum Sw.
• Hedysarum racemiferum J.F. Gmel.
• Hedysarum racemosum Aubl.
• Hedysarum supinum Sw.
• Meibomia adscendens var. incana (Sw.) Kuntze
• Meibomia cana S. F. Blake
• Meibomia incana (Sw.) Vail
• Meibomia supina (Sw.) Britton

International Common Names

• English: beggar's lice; creeping beggarweed; kaimi-clover; Spanish clover; tick trefoil; wild peanut; zarzabacoa comun
• Spanish: pega-pega; zarzabacoa comun
• French: colle-colle; gros treff; gros trefle; herb gallon; pois madame
• Portuguese: amor-de-campo; carrapicho-beico-de-boi; pega-pega

Local Common Names

• Cook Islands: piripiri
• Dominican Republic: amor seco
• Lesser Antilles: sweethearts
• Madagascar: famalakantsy; pelatsifotra; savisaha; tialamba
• Marshall Islands: lattil pako
• USA/Hawaii: ka'imi

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Fabales
•                         Family: Fabaceae
•                             Subfamily: Faboideae
•                                 Genus: Desmodium
•                                     Species: Desmodium incanum

The most commonly used synonym in the literature is Desmodiumcanum but this was the result of the incorrect use of an illegitimate basionym (Nicolson, 1978). Sometimes the authority for D. incanum is given as (Sw.) DC, but this is also incorrect. That name refers to a different taxon which is either Desmodium mauritianum (ILDIS, 2013) or Desmodium ramosissimum; these being synonyms of each other.

Desmodium comes from the Greek word desmos which means a bond or chain. Kaimi (correctly Ka’imi) clover, the Hawaiian name for the plant, means 'seeker'. The other English names, which refer to lice and ticks, relate to the sticky seeds that stick to clothes and pets like those pests. The number of common names for the plant in Madagascar implies that it is a common, well-known plant there (ILDIS, 2013).

The following description is from Wagner et al. (1999):

Prostrate, ascending, or erect subshrubs or shrubs up to 1 m tall; stems pubescent with spreading hooked and longer straight hairs, glabrate. Leaves trifoliolate, leaflets subcoriaceous, usually elliptic or narrowly elliptic, terminal one 4-9 cm long, 1.5-4.5 cm wide, lateral nerves conspicuous, upper surface with minute hooked and straight hairs, lower surface densely appressed pubescent, apex obtuse or often acute, petioles 1-4 cm long. Flowers numerous in racemose inflorescences 5-12 cm long, rachis densely pubescent with minute hooked hairs, pedicels 3-10 mm long, persistent after articles fall, pubescent with minute hooked hairs; corolla pink to purplish, 5-6 mm long. Pods stipitate, (3) 4-5 (-8)-jointed, (2-) 2.5-3 (-4) cm long, densely pubescent with hooked hairs, articles nearly semicircular, 4-5 mm long, ca. 3 mm wide.

The following description is from Acevedo-Rodríguez (2005):

Decumbent or scandent herb, much branched from the woody base, attaining 1-1.5 m in length. Stems more or less cylindrical, appressed pubescent or pilose, glabrescent with age. Leaves alternate, trifoliolate; leaflets 3-9 × 0.8-3.8 cm, elliptical, oblong, ovate, lanceolate, or exceptionally rounded, chartaceous, involute, the apex obtuse or acute, mucronate, the base obtuse or rounded, the margins entire; upper surface dark green, puberulent; lower surface grayish green, strigulose, with prominent venation; petiolules 1.5-3 mm long, pilose; petioles 0.7-3 cm long, pilose, canaliculate; rachis 3-10 mm long, pilose, canaliculate; stipules ovate to lanceolate, 6-10 mm long, persistent; stipels minute, subulate. Inflorescences of terminal pseudoracemes, 10-18 cm long, pubescent; bracts minute, persistent. Calyx green, campanulate, 2.5-3 mm long, strigulose; corolla pink or pink-violet, the standard ovate, 5-6 mm long, retuse, unguiculate at the base, the wings and the keel as long as the standard. Legume uncinate-pubescent, 2-4 cm long, crenate on the ventral suture, with 5-8 fertile segments. Seeds 2.5-3.5 mm long, oblong elliptical, light brown. 

The timing of the spread of the plant in the tropics including most oceanic islands is unclear. For a short period during the twentieth century it was promoted as a forage plant and may have been intentionally planted, but its use and promotion has diminished since (Jones and Bunch, 2003; ILDIS, 2013). With its seeds being such able hitchhikers on clothes, socks, legs, shoes, shoe-laces, animals, pets and livestock, in most case it is likely to have spread accidentally.

D. incanum was first noted on Round Island, Mauritius, in 1987, and was probably introduced during invasive animal and plant management efforts (C. Griffiths, University of Bristol, UK, personal communication, 2013; Griffiths et al., 2013). Today it is prolific and widespread on Round Island. Both the Aldabran giant and Radiata tortoises consume large quantities of this legume, and as a result it has changed its growth form, becoming more prostrate (and possibly occupying more space). Seed productivity, however, has fallen where tortoises continually graze this species (C. Griffiths, University of Bristol, UK, personal communication, 2013).

D. incanum is frequently a significant component of productive grasslands, and is variously viewed as a secondary and valued forage or a weed both within and outside of its native range (Hacker et al., 1996; Jones and Bunch, 2003; Garbulsky and Deregibus, 2006; Guglieri-Caporal et al., 2010). Due to its nitrogen-fixing abilities it is possible that it has an impact on soil nutrient cycles (these could be viewed as positive or negative), but no studies quantify this, or any possible consequences to co-occurring species – not even in the studies of it as a forage. It is a common weed of slash and burn agriculture, and disturbed secondary vegetation (Dalle and de Blois, 2006; Mitja and Miranda, 2010; Randriamalala et al., 2012). It is widespread in many regions where it occurs, but rarely the most significant weed (e.g. Lárez Rivas, 2007). Some costs may be offset at the most minor scales by the benefits derived from its use as a diuretic and anti-inflammatory (Vargas et al., 1991).

On the Big Island of Hawaii (USA), ranchers on (windward) Big Island welcome D. incanum in the pasture. It disappears after about two years of continuous cattle grazing, but comes back vigorously when the field is rested. It does well in a mix with California grass (Urochloa mutica), which also gives way to Paspalum conjugatum after a year or two without steady rotation. D. incanum is also controlled by mowing on coffee farms in the South Kona area of Big Island. 

Some extension offices in universities and state government, as well as lawn management companies in North America, describe its identification, control and management as a lawn weed (e.g. University of Florida Extension Office, 2013).

Impact on Habitats

D. incanum is known to occur in disturbed places on both inhabited and uninhabited islands of the Pacific, and while it is often widespread, it is rarely more than locally abundant (Whistler, 1998; Starr and Starr, 2006; Starr et al., 2006; US Forest Service, 2014). The offshore islands and islets of Hawaii are mainly protected areas and provide a habitat for seabirds. It occurs in protected areas in Hawaii on Molokai at Kalaupapa National Historic Park (Medeiros et al., 1996) and on Maui in Haleakala National Park (Welton and Haus, 2008), but is simply listed with a suite of other invasive species and no negative impacts are attributed to it alone. This weed is occasionally controlled in Hawaii in conservation areas, where it is never a major component. It tends to grow alongside trails and fence lines, but does not do well under the forest canopy (J. Beachy and S. Kaye, Big Island Invasive Species Committee, Hawaii USA, personal communication, 2013). Its control is usually for its nuisance value and because conservation workers do not want to see it even as a trailside weed in more pristine areas. A congener Desmodium tortuosum is viewed as a more significant (and already widespread) problem in Hawaii (J. Beachy and S. Kaye, Big Island Invasive Species Committee, Hawaii USA, personal communication, 2013).

The plant occurs in important habitats in Florida, including pine rockland (Green et al., 2008), dry prairies (Orzell and Bridges, 2006), Cedar Key State Reserve (Amoroso and Judd, 1995)and in various protected areas (e.g. Hubbard and Judd, 2013)including the Castillo de San Marcos National Monument (Zomlefer and Giannasi, 2005). It is a significant weed along roads, trails and disturbed areas in Guana Tolomato Matanzas National Estuarine Research Reserve but doesn’t overly compete with important species, or in relatively intact native plant communities (E. Montgomery, Hawaii Invasive Species Council, Hawaii USA, personal communication, 2013). It is widespread in the lower two-thirds of the state of Florida and is also documented in several of the northern counties (Wunderlin and Hansen, 2012), and so its occurrence in protected areas is unsurprising.

Impact on Biodiversity

D. incanum has been listed as co-occurring with important species of conservation concern in the Galapagos (Linum cratericola), where it may or may not be native (Simbaña and Tye, 2009). However, it is not described as a threat to these species. Similarly, it is listed as an invasive species in cockaded woodpecker (Picoides borealis) habitat on land used by the military for training, but is likely to pose little or no threat to the woodpecker or the vegetation upon which the woodpecker depends (Guertin and Tess, 2006). It is listed as one of many non-native species co-occurring with the threatened endemic species in Florida including Harrisia aboriginum, Argythamnia blodgettii and Indigoferatrita subsp. scabra (Bradley et al., 2004; Hodges and Bradley, 2006). The presumed mechanism for an impact is via competition, but no clear indication of it being a significant threat is given. In Hawaii, there is one instance where D. incanum threatens conservation values, where it (along with other non-native species) has invaded the West Maui population of Tetramolopium sylvae (Hank Oppenheimer, Maui Nui Plant Extinction Prevention Program, Hawaii USA, personal communication, 2013).

Mainly a scourge for parents who have to pick it out of their children’s socks (and their own), and it frequently attaches to shoe laces, and trouser bottoms. It is best described as a major nuisance.

Conservation managers with awareness of the issue try not to spread weeds of any kind to pristine areas, and the diligence required can be time-consuming and stressful.

• Invasive in its native range
• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Long lived
• Fast growing
• Has high reproductive potential
• Reproduces asexually

• Ecosystem change/ habitat alteration
• Increases vulnerability to invasions
• Modification of nutrient regime
• Negatively impacts agriculture
• Negatively impacts livelihoods
• Reduced amenity values
• Reduced native biodiversity
• Threat to/ loss of endangered species
• Threat to/ loss of native species

• Competition - monopolizing resources
• Competition (unspecified)
• Pest and disease transmission
• Herbivory/grazing/browsing
• Rapid growth
• Produces spines, thorns or burrs

• Highly likely to be transported internationally accidentally
• Highly likely to be transported internationally deliberately
• Difficult to identify/detect as a commodity contaminant
• Difficult/costly to control

Economic Value

In pastures it has been promoted as a useful nitrogen-fixer and a source of fodder with extra protein. It may be useful because it survives herbivory, some herbicide applications, and dry conditions (Smith, 1995; Schifino-Wittmann, 2000; Garbulsky and Deregibus, 2006; ILDIS, 2013; Tropical Forages, 2013). It is secondarily preferred by livestock, however, and therefore ranchers must invest effort in maintaining the preferred grasses (Bergin, 2003; Jones and Bunch, 2003).

Social Benefit

D. incanum is used as a diuretic, stomachic, febrifuge and hemostatic in Central America (Setyowati-Indarto and Brink, 1999).

Environmental Services

Despite its status as an invasive species in the Pacific (US Forest Service, 2014), the USDA continues to promote the planting of this species to establish ground cover, in the context of agricultural and biodiversity values and for soil conservation measures (USDA-NRCS, 2012).