Leaf:  Alternate, palmately compound with 3 leaflets; each leaflet oblong, lanceolate, oblanceolate or obovate, rounded at the tip, tapering to the base, up to 1 inch (2.5 cm) long; margin finely toothed; upper surface smooth or sometimes hairy, pinnately veined; lower surface with fine hairs pressed flat against the leaf. 

Flower:  Slender, tapering clusters with 30 to 80 flowers per raceme, each racemes up to 4 inches (10 cm) long;  appearing May through  November; each flower pea-like, 4 to 5 mm long, with 5 white petals, 10 stamens, and 5 green sepals, united below.     

Fruit:  Podlike legume; oval, cross-ribbed; slightly hairy to hairless, only a few millimeters long; dark brown to black at maturity; containing 1 or 2 hard, small seeds which may stay viable for 30 years.

Stem:  Upright, branched, usually smooth; 0.5 to 2.5 m tall.

Form:  Obligate biennial, loosely-branched forb.

Discussion

Melilotus alba is the scientific name for the plant commonly known as white sweet clover.  Meli means "honey", lotus means "leguminous plant", and alba means "white".  The common name "clover" comes from the Latin "clava" meaning "club", as the three-part clover leaf resembled Hercules's three-knobbed club.  Clava became clover, but we still call the clovers on playing cards "clubs".  Interesting.

 White sweet clover is native to Europe and Asia, and was introduced to North America in the 1600s.

This plant attracts bees with its abundant nectar and sweet vanilla fragrance. 

White sweet clover indicates disturbance if it is found in a prairie. 

In agriculture, white sweet clover is planted as a green manure to improve the soil, as a hay crop, and for pasture.  Hay from white sweet clover may be toxic if it is not cured properly.  White sweet clover roots are referred to as "harbor roots" because they have nodules that house nitrogen- fixing bacteria.

People have used the crushed leaves for its fragrant smell in sachets and potpourri.  

Distinguishing Characteristics

White sweet clover has 3-part leaves with pea-like flowers in slender, tapering clusters and net-veined pods.  The leaves are fragrant.

Associated Plants

Thistle (Cirsium arvense), Queen Anne's lace (Daucus carota), yellow sweet clover (Melilotus officinalis), and curly dock (Rumex crispus). 

Distribution

White sweet clover is distributed throughout the United States, including Alaska and Hawaii.  It grows readily along roadsides, in fields and pastures, on abandoned acreage, and in prairies or grasslands.  Our example was on a vacant lot which was the former location of a gas station.  White sweet clover occurred in several sizeable groupings on this lot. 

Images

Click each small picture to see a larger image. 

November, 2003 BS	November, 2003 EK	November, 2003 BS	November, 2003 EK
November, 2003 EK	November, 2003 BS	November, 2003 EK

Location

N 39.27955°    W -89.89064° 
Beside McDonald's in the empty lot on W. Main, Carlinville, Macoupin County, IL.

Copyright

Photos © 2003 Elsa Kleeman and Bill Steinman, Carlinville High School, linke@carlinvilleschools.net       
          
References

Stubbendieck, James, Geir Y. Friisoe, and Margaret R. Bolick.  1994.  Weeds of Nebraska and the Great Plains.  Nebraska Dept. of Agriculture, Bureau of Plant Industry, Lincoln.  589 pp.

Mohlenbrock, Robert H. 1981. Wildflowers of fields, roadsides, and open habitats of Illinois.  Illinois Dept. of Conservation, Division of Forest Resources and Natural Heritage, Springfield.  226 pp.

Peterson, Roger Tory and Margaret McKenny. 1968. Wildflowers. Houghton Mifflin Company, Boston. 420 pp.

Venning, Frank D. 1984. Wildflowers of North America.  Western Publishing Company, Inc., Racine (WI).  340 pp.

Edsall, Marian S. 1985.  Roadside plants and flowers.  The University of Wisconsin Press, Madison. 143 pp.

The Noble Foundation Plant Image Gallery
http://www.noble.org/imagegallery/Forbhtml/WhiteSweetClover.html

Oklahoma Biological Survey
http://www.biosurvey.ou.edu/okwild/whtsweet.html

Forage Information System, Department of Crop and Soil Science, Oregon State University
http://www.forages.css.orst.edu/Topics/Species/Legumes/White_Clover/

Maggie Cole.  Illinois Nature Preserves Commission
http://www.inhs.uiuc.edu/chf/outreach/VMG/wysclover.html

Virginia Tech Weed Identification Guide
http://www.ppws.vt.edu/scott/weed_id/meual.htm

Missouri Wildflowers
http://www.missouriwildflowerguide.com/Flowers/WhiteSweetClover.html

Minnesota Department of Natural Resources
http://www.dnr.state.mn.us/herbaceousplants/WhiteSweetClover.html

 Click here to return to the plant list for Carlinville High School's South-Central Illinois flora studies.