Eclipta prostrata

Eclipta prostrata
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta - Flowering plants
Class:	Magnoliopsida - Dicotyledons
Order:	Asterales
Family:	Asteraceae ⁄ Compositae
Genus:	Eclipta
Species:	E. prostrata
Binomial name
Eclipta prostrata (L.) L.
Natural range of Eclipta prostrata from USDA NRCS Plants Database.

Common name: false daisy

Taxonomic notes

Eclipta comes from the greek word "ekleipta" (deficient) which refers to the absence of the pappus on the achene (Fernald 1950).

Description

A description of Eclipta prostrata is provided in The Flora of North America.

E. prostrata is an annual and can be a short-lived perennial in warmer climates. The reddish-purple stems are covered with short, stiff hairs and can grow prostrate or decumbent and branch occasionally. The leaves are subsessile, elliptic-lanceolate and arranged opposite, with a few blunt teeth along the margin . 1-3 composite flower heads on short pedicels emerge from the axils of the leaves. The ray florets are white, narrow, and short while the disk florets are cream with four small spreading lobes with pale yellow or light brown anthers emerging from them. The bracts form the base of the flowerhead and are green and triangular.

It is a noxious weed in many agricultural crops such as soybean, cotton, rice, sugarcane, peanut, and corn (Chauhan and Johnson 2008).

Distribution

It is native to the Southeastern United States, but can also be found in Asia and South America (Holm et al. 1997).

Ecology

Habitat

Eclipta prostata can be found in shallow water in shaded Acer-Nyssa-Taxodium swamps; cypress depression swamps; marsh edges; lake shores; river banks; brackish marshes; seepage areas in calcareous talus; moist sandy-peaty clearings of Baccharis flats; sandy loam of coastal hammocks; pine flatwoods; and river floodplains (FSU Herbarium).It is a noxious weed in many agricultural crops such as peanuts, soybean, cotton, rice, sugarcane and corn (Chauhan and Johnson 2008). E. prostrata favors moist conditions and has been observed in gardens, holding ponds, and drainage ditches (FSU Herbarium). Substrate types include sandy peat, loamy sand and sandy loam soils (FSU Herbarium). Associated species include Typha, Erechtites, Ludwigia, Juncus, Mitreola, Fuirena, and Rhynchospora (FSU Herbarium).

Phenology

It has a composite flower head that consists of 8 to 16 green triangular bracts; narrow, white ray florets; and cream short disk florets with yellow or light brown anthers protruding. Flowers June through November (FSU Herbarium).

Achenes are oblong, truncate at the top and tapering to a well rounded tip at the bottom and develop in a flowerhead after the petals fall off.

Seed bank and germination

E. prostrata is a noxious weed in agronomic crops and container grown plants (Gleen et al. 2006). Seeds favor saturated conditions foer germination and are strongly photoblastic, no seeds will germinate without light (Chauhan and Johnson 2008). Germination can occur over a range of temperatures from 10 to 35 C; however, germination has observed to have the highest rate (83%) at a constant temperature of 35C. In peanut fields, it has been observe to germinate in the summer; and early rainfall, irrigation or wetter seasons favor germination in peanut fields (Altom and Murray 1996).

Pollination

The following Hymenoptera families and species were observed visiting flowers of Eclipta prostrata at Archbold Biological Station (Deyrup 2015):

Colletidae: Hylaeus confluens

Halictidae: Halictus poeyi, Lasioglossum placidensis, L. puteulanum, L. tamiamensis

Sphecidae: Cerceris tolteca, Ectemnius rufipes ais

Vespidae: Parancistrocerus perennis anacardivora, P. salcularis rufulus, Stenodynerus fundatiformis

Use by animals

Leaves contain nicotine, which acts as an insecticide.

Diseases and parasites

It is a hosts for diseases to agricultural crops and other species. It is a host for Sclerotinia blight which is caused by the fungus Sclerotinia minor which infests 25% of Oklahoma's peanut crops (Altom and Murray 1996). It is also a host of Amsacta moorei which feeds on young sorghum and castor beans (Chauhan and Johnson 2008).

Reniform nematodes occasionally attack roots.

Conservation and Management

Early control is necessary to prevent competition (Kranz et al. 1977). It is difficult to control with soil applied herbicides including metolachlor, imazethapyr, and vernolate (Grichar et al. 2000). Diclosulam and flumioxazin are able to control effectively when applied at 27 g ai/ha or 105 g/ha respectively (Jordan et al. 2009).

Cultivation and restoration

E. prostrata is a noxious weed in agricultural crops and container grown plants. Container grown landscape plants are vulnerable because they are typically grown in organic substrate and are irrigated frequently, conditions that E. prostrata favors for germination (Wehtje et al. 2006). Roots can become established at the drainage holes of potted plants, keeping it protected from POST applied herbicides such as halosulfuron. The crown and lateral branches of E. prostrata are regenerative and make it more tolerant of halosulfuron applications.

Peanut are slow growing, making E. prostrata a competitor due to its ability to develop a canopy faster than the peanut (Grichar et al. 2000). It has also been observed to be a contaminant in rice seeds in the Philippines and reduce crop yields (Rao and Moody 1990).

It is claimed to be a powerful liver tonic.

References and notes

Chauhan, Bhagirath S., and David E. Johnson. “Influence of Environmental Factors on Seed Germination and Seedling Emergence of Eclipta (eclipta Prostrata) in a Tropical Environment”.Weed Science 56.3 (2008): 383–388.

Deyrup, M.A. and N.D. 2015. Database of observations of Hymenoptera visitations to flowers of plants on Archbold Biological Station, Florida, USA.

Fernald ML, 1950. Gray's Manual of Botany. 8th Ed. New York, USA: American.

Florida State University Robert K. Godfrey Herbarium database. URL: http://herbarium.bio.fsu.edu. Last accessed: October 2015. Collectors: Loran C. Anderson, Linnea Angermuller, Sydney T. Bacchus, Kurt E. Blum, D. Burch, Andre F. Clewell, A.H. Curtiss, J.A. Duke, J. Dwyer, R.K. Godfrey, Ann F. Johnson, G.R. Knight, R. Kral, Robert L. Lazor, S.W. Leonard, H. Loftin, J.R. Martinez, Herbert Monoson, C. Nelson, R.A. Norris, Paul L. Redfearn Jr., Grady W. Reinert, Manuel Rimachi Y., Deborah R. Shelley, Sidney Thompson, Edwin L. Tyson, D.B. Ward. States and Counties: Florida: Bay, Brevard, Calhoun, Citrus, Dixie, Flagler, Franklin, Hernando, Jackson, Jefferson, Lake, Lee, Leon, Liberty, Madison, Martin, Sarasota, Seminole, Wakulla, Washington. Georgia: Grady. Country: Columbia, Honduras, Panama, Peru. Compiled by Tall Timbers Research Station and Land Conservancy.

Glenn R. Wehtje et al.. “Potential for Halosulfuron to Control Eclipta (eclipta Prostrata) in Container-grown Landscape Plants and Its Sorption to Container Rooting Substrate”. Weed Technology 20.2 (2006): 361–367.

Holm LG, Plucknett DL, Pancho JV, Herberger JP, 1977. The World's Worst Weeds. Distribution and Biology. Honolulu, Hawaii, USA: University Press of Hawaii.

John V. Altom, and Don S. Murray. “Factors Affecting Eclipta (eclipta Prostrata) Seed Germination”. Weed Technology 10.4 (1996): 727–731.

Jordan, David L. et al.. “Peanut and Eclipta (eclipta Prostrata) Response to Flumioxazin”. Weed Technology 23.2 (2009): 231–235

Rao AN, Moody K, 1990. Weed seed contamination in rice seed. Seed Science and Technology, 18(1):139-146

W. James Grichar et al.. “Weed Control with CGA-152005 and Peanut (arachis Hypogaea) Response”. Weed Technology 14.1 (2000): 218–222.